What is the meaning of "Lo Yecheratz Kelev Leshono"?
Rashi #1: It means that no dog will whet (sharpen) its tongue (and bark). 1
Rashi #2 (to Shmuel II 5:24): It is an expression of speech (in dog language), or of raising one's voice.
Rashbam: It means that throughout Bnei Yisrael, no dog will bark.
Targum Onkelos and Targum Yonasan: It means that no dog will damage with its tongue -by barking at a Yisrael or at his animals.
Oznayim la'Torah: With reference to the Egyptians, it means that the servants of Pharaoh will not object; they will not say "Lechu Na ha'Gevarim!" (10:11); or "Rak Tzonechem u'Vekarchem Yutzag!" (10:24). 2
Mechilta (in Mishpatim): This explains why (as a reward) the Torah in Shemos 22:30 writes that one should throw a Tereifah to the dogs - to teach us that 'Hashem does not withhold the reward of any creature.'
Oznayim la'Torah: Which will also explain why the Torah adds, "l'me'Ish v'Ad Behemah."
Why is it so noteworthy that no dog will bark?
Moshav Zekenim #1 and Hadar Zekenim #1: Because dogs normally bark when they hear people dying.
Moshav Zekenim #2: Because they normally become very excited and brazen when there are corpses around.
Moshav Zekenim #3, Riva (citing Rabeinu) and Hadar Zekenim #2: Because Yisrael were commanded to take their sticks, which would normally have caused the dogs to bark. 1
Moshav Zekenim #4: Because they should have naturally barked at the animals of Yisrael.
Moshav Zekenim #5: Because dogs normally bark at midnight. 2
Moshav Zekenim #6 (citing R. Chaim), Riva (citing R"M of Kutzi), Rosh, Hadar Zekenim #3 and Da'as Zekenim: Because they normally bark when the angel of death 3 is in the city. 4 Here, he was in the city to kill the Bechoros. They did not bark, due to the honor of Yisrael.
Oznayim la'Torah: Either because of the Mal'ach ha'Maves that came down to Egypt, or because of the smell of corpses. 5
Gur Aryeh (to 22:30): Dogs are far removed from the world's reality; they not considered part of it. Yetzias Mitzrayim perfected the world as a whole to such a degree, that all of existence agreed - even the dogs, 6 who did not bark.
Moshav Zekenim: This is difficult, since Yisrael did not leave until morning! (The Pasuk discusses at night, since the next Pasuk states that Pharaoh's servants will come to Moshe to tell them to leave. (PF)
Riva and Hadar Zekenim, both citing R. Menachem: They normally bark at night, as the Gemara states in Berachos 3a.
See Bava Kama 60b.
Oznayim la'Torah: Neither of which applied in Goshen, which explains why they did not bark in Goshen. Others explain because, even though dogs normally bark at the end of the second watch of the night - refer to 11:7:151:5 - they did not bark in honor of Yisrael, so that Yisrael, who did not leave their houses all night, should not think that the Mal'ach ha'Maves had come to Goshen. This in turn explains why the dogs were rewarded. Refer to 11:7:1:1*.
More about dogs in Maharal's thought - a. Gur Aryeh (to Bamidbar 4:13) - Dogs are associated with Midas ha'Din. b. Maharal (Gevuros Hashem, beg. Ch. 32, p. 121) - Dogs are apart from the majority of creatures; all keep their distance. c. Maharal (Be'er ha'Golah, Be'er #5, p. 98-99) - Dogs are the least, lowliest animals, far removed from man (also refer to Bereishis 8:17:1.4:1). That is why they holler and howl more than other animals. d. Maharal (Nesivos Olam, Nesiv Gemilus Chasadim Ch. 5, p. 167) - Every creation has an aspect of good and kindness- except for the dog. "One who raises a bad dog removes from himself fear of Heaven" (Shabbos 63a); since Hashem is the Prime Cause of all existence, which the dog does not take part in, so one ought not connect with such a creature. That is why the dog loves its master - it is under its master, rather than under its Creator. (But see Horayos 13a - "Why does a dog recognize its master, whereas a cat does not?" Maharsha (loc. cit.) - Opinions differ as to whether the Gemara means the dog's human master, or its Creator. Maharal (Chidushei Agados Vol. 4, p. 60, loc. cit.) - A Kelev is a Ba'al Nefesh with Hakarah (sense, recognition); in Leshon Kodesh, Kelev is a contraction of 'Kulo Lev' (all heart).) (EK) e. Maharal (Gevuros Hashem ibid.) - A Rasha is compared to a dog (Tehilim 59:7). Pharaoh himself was compared to a dog, fit to be beaten by the Mateh (refer to 7:9:6:3).
