“And I (G-d) will send the hornet before you, and it will drive out the Chivi and the C’naani and the Chiti from before you” (Sh’mos 23:28). There are three times in Tanach where the hornet (as opposed to bees) are mentioned, and all three are regarding the conquest of the Promised Land. Besides the verse in our Parasha, Moshe mentions it in his address to the nation shortly before his death, telling them not to fear the nations of C’naan, but instead to remember the mighty and wondrous things that G-d did to Pharaoh and Egypt, as G-d will do similar things to all the nations they fear (D’varim 7:19). He then adds (7:20) “and in addition, Hashem your G-d will send the hornet against them, until all of those who remain and are hidden from you are destroyed.” The third mention comes at the end of Sefer Y’hoshua (24:12), as part of G-d’s message to the nation in Y’hoshua’s address/challenge to them shortly before his death. There, the hornet (used in the singular form all three times because it refers to the species) was said to have driven out the kings who dwelled on the eastern side of the Jordan River, even though the previous verse (24:11) mentions crossing to the western side of the Jordan and conquering the nations there.
There are numerous issues related to the biblical mentions of the hornet that deserve a closer look; I will attempt to deal with some of them here. First and foremost is whether the verses are literally referring to hornets attacking our enemies, or meant figuratively, or not really referring to hornets at all. Rav Saadya G’on and Ibn Ezra both explain the word “tzirah” to refer to a physical illness, related to the word “tzora’as” (which is a physical condition, specifically a skin condition), not the flying insect. Ralbag understands “the hornet” to be a non-literal term used to refer to the extra-ordinary means G-d will use to defeat our enemies. Although in his commentary on Chumash the Malbim does not explain what “tzirah” refers to (with his silence implying that it refers to the flying insect), in his commentary on Y’hoshua he explains it figuratively, with our conquering the mighty kings of Sichon and Og on the eastern side of the Jordan instilling fear in the nations on the western side, who reacted as if there were hornets to fear.
Malbim’s approach works well to explain why defeating Sichon and Og was mentioned after defeating the nations on the western side (which happened later chronologically) had already been mentioned, as the victory on the western side was aided by the previous victories on the eastern side, victories which had an effect similar to hornets in that they instilled fear in the nations on the eastern side. It does not, however, explain what the first two mentions (in Sh’mos and in D’varim) are referring to. Although it is possible that the first mention, which was said before Sichon and Og were defeated, refers to the fear created by what happened to Egypt (see Sh’mos 15:14-16), and the second mention refers to the same fear as the third (based on what happened to Sichon and Og), the future tense (“will send the hornet”) implies that the fear hasn’t yet set in, and in both cases the circumstances that would have created that fear had already occurred. Additionally, the other nations being fearful was already mentioned explicitly (Sh’mos 23:27), so there is no need to also express it in figurative terms, and there is no reason for Moshe to specify that this fear would overtake “those who remained and those who are hidden” more than it would anyone else.
Rashi (see also Radak on Y’hoshua and Rabbeinu Bachye on D’varim 7:20) tells us that the “tzirah” is a flying insect, which seemingly means that he takes it literally. Although it’s possible that the term needs to be defined literally before we can understand how it applies allegorically, since no allegorical explanation is subsequently given, it is fair to assume that Rashi understood it literally. After defining them as flying insects, Rashi tells us that the hornets smote them in their eyes and injected venom into them, causing their death, which fits the description of what attacking hornets would do (except for the stings being specifically in the eyes, which is certainly possible — especially if being sent directly by G-d, but that’s a digression we will avoid for now). Rashi then adds a direct quote from the Talmud (Soteh 36a), that the hornets never crossed the Jordan River, a comment that has generated much discussion (starting with the Talmud itself). [It should be noted that Rashi’s quote of this statement is where, in the earliest editions of Rashi, his commentary on the verse ends. This is borne out by how Rashi is quoted by the earlier commentaries, e.g. Chizkuni, who quotes Rashi and then quotes the further explanation of the Talmud without mentioning that Rashi also quotes it.]
In the Talmud, the question is posed as to how it could be said that the hornets never crossed the Jordan if our verse (Sh’mos 23:28) says that G-d said He would “send the hornet before us.” Quoting this verse (rather than the one in D’varim) is interesting, from two perspectives. First of all, how does it prove that the hornets crossed the Jordan? Maybe it’s only referring to the wars with Sichon and Og, which took place on the eastern side, thereby negating the need for them to cross! Although some answer this question by pointing out that three of the seven nations are mentioned, and only two of them were on the eastern side (an issue that can bring about another digression), since the context of the surrounding verses is the conquest of all the nations (including those on the western side), including the next verse continuing by telling us that the nations that the hornets will drive out will “not be driven out in one year, lest the land be desolate and the beasts of the field become abundant,” it is obvious that the hornets will not be operating on just one side of the Jordan. The second reason why using this verse is interesting is that the verse from D’varim would seem to be a better choice. Why prove that the hornets also operated on the western side of the Jordan from the verse in Sh’mos, when the one in D’varim was said after Sichon and Og had already been conquered, and therefore must be referring to conquering the land on the other side of the river?
In order to explain how it can be said that the hornets never crossed the Jordan if the verse says they did, Reish Lakish suggests that they stayed on the eastern side and shot their poison over the Jordan to the western side, where it blinded the nations there and rendered them incapable of having children. Although technically this answers how the hornets could impact the war on the western side if they never crossed the river, practically speaking, it’s impossible. Yes, I know, nothing is impossible when G-d is involved, but since He almost always operates within the rules of nature that He, in His infinite wisdom, set up and operates (see https://rabbidmk.wordpress.com/2012/10/11/parashas-bereishis-5773/), and hornets inject their venom into their victims by stinging them (and, even if they could access their venom, or that of other creatures, in other ways, throwing them across a river seems rather unlikely), this answer doesn’t seem to hold water (pardon the pun). Besides, since the nations on the western side were to be defeated slowly, why have this miraculous venom tossing — with each subsequent toss being made further and further west — done repeatedly, rather than just allowing the hornets to cross?
Rav Papa gives a different answer, suggesting that there were two separate groups of hornets, one during Moshe’s time and one during Y’hoshua’s, with Moshe’s hornets not crossing the Jordan and Y’hoshua’s crossing. Therefore, the verses that discuss defeating the nations on the western side are referring to Y’hoshua’s hornets, while the statement that says the hornets didn’t cross is referring to Moshe’s. Although this approach seems much more straightforward, it has one glaring weakness; why is there no mention of these hornets in Sefer Y’hoshua, when the land on the western side being conquered is discussed? It’s possible, though, that Y’hoshua’s hornets were not as out of the ordinary as Moshe’s; their role was, as implied in D’varim, to clear out the individuals who were hiding. When they hid underground or in caves, they inadvertently (from their perspective; G-d made sure it occurred that way) disturbed hornets nests, causing the hornets to chase after them and either sting them or bring them out into the open where the nation could take care of them. Since these were a different set of hornets, with a different purpose, the Talmud could not use them to prove that the hornets described in Sh’mos crossed the river, nor were they out of the ordinary enough to be included in Y’hoshua’s description of these conquests. Rav Papa was suggesting that the verse in Sh’mos was referring to both sets of hornets, with only the second kind “crossing” to the western side.
Getting back to Reish Lakish’s approach, I would suggest that he also understood the hornets literally, as G-d sent real hornets to defeat Sichon and Og. These hornets accomplished two things; they stung the soldiers of Sichon and Og’s armies, thereby helping to defeat them, and, in doing so, created a fear in the rest of the nations of C’naan, including those on the western side of the Jordan. Since this fear was created by the hornets, it is described as their “venom,” which was figuratively “thrown across the river” to affect those on the other side, where it “blinded them,” i.e. made it impossible for them to see how they could be victorious, and caused them to lose their virility, similar to how Rachav described how her people were affected by their fear of the Israelites (see Rashi on Y’hoshua 2:11). This fear, described in D’varim and Y’hoshua as being caused by the hornets helping defeat Sichon and Og, could not prove that Moshe’s hornets crossed the Jordan, so the Talmud quotes the verse in Sh’mos. Reish Lakish was suggesting that this long term effect of the hornets, the fear that they created, was being referred to there as well.
As far as why this fear is described in D’varim as targeting “those who remained and those who are hidden” more than anyone else, Reish Lakish may understand the verse to be describing the length of time the fear created by Moshe’s hornets would last, not who they would affect; it would last “until all who remained,” including “those who hid themselves,” so were able to stay alive longer, “were destroyed.” This is also why it was stated in the future tense even though it had already occurred, as Moshe was describing how long the fear would last, not that it would come about. It was the fear created by real hornets that crossed the Jordan, with the real hornets staying on the eastern side.