Why does the Torah write "Lo Ye'achlu" rather than "Lo Yochlu"?
Rashi: To implicate someone who feeds Tamei species to a Katan. 1
Since it means 'it shall not be eaten through you' (Rashi).
Why does "Lo Ye'achlu" not come to include an Isur Hana
Rashi: Because the Torah will write in Re'ei Devarim, 14:12 "Lo Yochlu", 1 to preclude Isur Hana'ah.
See Sifsei Chachamim.
Why does the Torah list the Tamei birds (here) but the Tahor birds - in Devarim 14:4 & 5?
Rashi (Devarim 14:5): Because it always presents the shorter list.
Ramban: It lists the (twenty-four species of) Tamei birds and the eight Tamei Sheratzim (rodents - in Pasuk 29, 30), because the list is comprehensive, and it is therefore not necessary to give the Simanim. 1
The Torah lists the Tahor Beheimos and Chayos in Devarim, even though it gave Simanei Kashrus, because it did not give Simanim to distinguish Chayos, whose Cheilev is permitted, from Beheimos, whose Cheilev is forbidden. (PF)
What do all the forbidden birds have in common, that explains why the Torah forbids them specifically?
Ramban #1: Because all twenty-four birds in the list are Doreis 1 (they catch their prey and hold it down whilst they proceed to eat it alive), a clear indication that they are cruel, 2 and someone who eats them adopts their cruel nature. 3
Ramban #2 and Seforno (on Pasuk 4): Refer to 11:4:1:2.
Targum Yonasan, Chulin 3:6: All birds that do not have an extra claw and a crop and whose gizzard (stomach) cannot be (easily) peeled 4 are forbidden. 5 .
With the sole exception of either the Peres or the Ozniyah (two species of vulture), whose blood is nevertheless hot due to the hot climate of the areas in which it lives (Ramban).
Ramban: It is this streak of cruelty that heats their blood, which in turn, causes one who eats them to become hot-blooded and cruel. (Even though blood of all birds and animals is forbidden, the Torah permits blood that never left the flesh (Shulchan Aruch YD 67:1), or was cooked (Menachos 21a). - PF)
Ramban: Perhaps the same applies to the Tamei species of animals, since all the animals that chew their cud and possess cloven hoofs are not Doreis (since they do not eat other creatures), whereas all the other species are.
Abarbanel (on Pasuk 1) - a crop and a gizzard that can be peeled enable grinding the food later like animals that chew the cud (refer to 11:4:1:3 & 4), whereas an extra claw indicates that it is not Doreis (refer to 11:13:1:1). Sh'lah ha'Kadosh (17, and Hagahah): An extra claw enables holding and guarding food very well. A crop and a gizzard that can be peeled show that it guards what it ate, to benefit from it. And the Neshamah of the eater is weakened if the body is soiled 5
. Through eating birds which have an evil nature (PF). The Sh'lah adds that legs (in locusts) to jump enable eating what is found on the land; others fly and destroy trees.
Oznayim la'Torah: As opposed to doves and pigeons which possess all the above Simanim and which are therefore permitted
Why does the Torah not list the Simnei Taharah of the birds, as it does by the animals, the fish and the locusts?
Oznayim las'Torah: Because the Simanim themselves are not conclusive and one needs to know the names of the Tamei species anyway. 1 .
Oznayim la'Torah: A bird with one Siman is Tahor- provided one recognizes Peres and Ozniyah (which have one Siman and are Tamei; with two Simanim, it is Tahor
What is a Nesher? Why is it called by that name?
Chizkuni: It is an eagle, 1 and it is called Nesher because it sees from afar - like "Ashurenu" in Balak Bamidbar, 23:9, 24:17.
Ba'al ha'Turim: An eagle, the king of the birds, 2 is called Nesher because it sheds its plumage every few years. 3
Riva: It cannot be an eagle, since the Gemara in Chulin, 61a states that a Nesher does not have any Siman of Taharah, and an eagle has an Etzba Yeseirah! Ran (Chulin 20b) - Rashi explainss that the Etzba Yeseirah is an extra toe at the back of the foot, which an eagle possesses. Others mainatain that it is bigger than the other toes, whereas according to the Ra'avad (Teshuvah 14) it is higher than the other toes.
Which is why the Torah mentions it first (Ba'al ha'Turim); also because it possesses none of the four Simnei Taharah
