Rashi on Leviticus 1:17/רש"י על ויקרא א׳:י״ז

1ושסע AND HE SHALL CLEAVE [IT] — The term שסע is used only for rending with the hands. Similarly it states in the story of Samson (Judges 14:6) “and he rent him (וישסעהו) as he would have rent a kid” (Zevachim 65b).

2בכנפיו means: he shall rend it together with its feathers he need not pluck out the feathers that form its plumage before doing so.

3בכנפיו means actually the feathers (not the wings). But surely you will not find even a common sort of man who can smell the odour of burnt feathers without being disgusted with it! Why, then, does Scripture say that it shall be offered with the feathers? In order that the altar should appear full up, as it were, and adorned with the sacrifice of the poor (since the bird with its feathers makes a finer show than without them) (Leviticus Rabbah 3:5).

4לא יבדיל BUT HE SHALL NOT SEPARATE IT — he must not break it entirely into two pieces, but only rends it from behind. — It is stated here of a bird-offering “a pleasing odour [to the Lord]” and it is stated (v. 13) of an animal-sacrifice “a pleasing odour [to the Lord]”, to tell you: whether one offers much or little it is equally pleasing to God provided that he directs his heart to Heaven (Sifra, Vayikra Dibbura d'Nedavah, Section 9 7; Menachot 110a).