Emor: Say Mother, please

the reason in both of them is that we should not have a cruel heart and [then] not have mercy, or that the verse should not permit us to be destructive to destroy the species, even though it allowed slaughter within that species. And behold, one who kills the mother and the children on one day or takes them when they are 'free to fly' is as if he cuts off that species.

MISHNA: One who recites Just as Your mercy is extended to a bird’s nest, as You have commanded us to send away the mother before taking her chicks or eggs (Deuteronomy 22:6–7), so too extend Your mercy to us; We silence him.

And one said that this was because he transforms the attributes of the Holy One, Blessed be He, into expressions of mercy, when they are nothing but decrees of the King that must be fulfilled without inquiring into the reasons behind them.

there are explanations for all of the commandments...As they wanted to say that there is no gain in the commandment for the Holy One, blessed be He, Himself, may He be elevated; but [rather] the gain is for man himself - to prevent him from damage or a bad belief or a disgusting character trait...and what gain and honor to the Creator is there, may He be blessed, from the neck more than from the back or [from] stabbing...they elucidated that even the lulav and the sukkah and the tefillin - that He commanded that they be 'a sign upon your arm"...are not for the honor of the Lord, may He be blessed, but [rather] to have mercy on our souls...And so [too], it stated in the Torah (Deuteronomy 10:13), "for your good,"...And so that which they said (Berakhot 33a), is to say that God did not worry about the nest of the bird and His 'mercy did not reach' it and its child; as His mercy does not extend to creatures with an animal soul, to prevent us from doing what we need to them. As were it so, slaughtering would be forbidden. But [rather], the reason for the proscription is to teach us the trait of mercy and that we not become cruel.