Hadithcore
Musnad Ahmad 2049
sahih

It was narrated that Ibn 'Abbas said: The Messenger of Allah (ﷺ) said:

"If you send out the (hunting) dog and it eats some of the prey, do not eat it for he only caught it for himself. But if you send him out and he kills (the prey) but does not eat any of it, then eat it, for he killed it for his master."

References1 variant
Arabic/English book
Book 25, Hadith 2049