Chulin, 139b: It may be eaten, because, knowing that one is liable to not take the eggs, the Torah would not command to send away the mother, thereby causing people to sin. ¹

Chulin, 141a: "Shal'each" implies even a hundred times, ¹ and "Teshalach" teaches us that the obligation to send the mother bird away applies even if one wants the babies for a Mitzvah.

Chulin 138b: The very obligation of sending away teaches us that Kodshim birds - which one is obligated, not to send away, but to bring to the treasurer of Hekdesh - are not subject to the Mitzvah of Shilu'ach ha'Ken. ²

Chulin, 141b: As soon as it leaves his hands ¹ he is permitted to take the eggs.

Chulin, 140a: It implies 'take for yourself, and not for your dog''

Chulin, 141a: He is not permitted to do so, since the Torah specifically writes "Shale'ach Teshalach es ha'Eim ve'es ha'Banim Tikach lach", and not vice-versa. ¹

Rashi #1: We learn from it that if this is the reward that the Torah gives for an easy Mitzvah that costs nothing ¹ , how much more so for Mitzvos that are difficult (and costly) to keep.

Rashi #2 (in the original manuscript): From here the Chachamim learned that one should 'Reckon what one loses by performing a Mitzvah against what one gains'. Be careful about a light Mitzvah like a severe one, since the Torah writes by both Shilu'ach ha'Kein and by Kivud Av va'Eim "Veha'arachta Yamim". ²

Seforno: We learn from it that even for the small measure of Chesed involved in not destroying the species, ³ by sending away the mother bird, one reaps the benefits in this world, whilst the principle is reserved for the world to come.

Targum Yonasan: "Lema'an Yitav lach" implies 'in this world', and "Veha'arachta Yamim", 'in the world to come'. ⁴

Hadar Zekenim: If you send the mother, it will be good for you, since it will give birth to more litters, and you will find them, and you will cause the mother to live a long life.