מדרש אויף ויקרא 8:25

23) (Vayikra 8:25): "And he took the fat": There is no thing (i.e., there is no gift given to a man) where there is no mitzvah for the L–rd (Thus, "And he took the fat, etc."): Fruits have many mitzvoth: terumoth, ma'asroth, challah, bikkurim, leket, shikchah, and peah. The gates of houses and of provinces have their mitzvoth to the L–rd, (Devarim 6:9): "And you shall write them on the doorposts (mezuzoth) of your house and on your gates."

24) Garments have their mitzvah to the L–rd, viz. (Devarim 22:11): "You shall not wear sha'atnez." A ta'alith, (Devarim 22:12): "Fringes shall you make for yourself."

25) A clean beast has its mitzvah to the L–rd, viz. (Devarim 15:19): "Every firstling (bechor) which is born in your herd and in your flock, the male, shall you consecrate to the L–rd your G d."