Genesis 37:31

37:31 So they took Joseph’s tunic, killed a young goat, ¹  and dipped the tunic in the blood.

Genesis 37:33

37:33 He recognized it and exclaimed, “It is my son’s tunic! A wild animal has eaten him! ²  Joseph has surely been torn to pieces!”

[37:31]  ¹ sn It was with two young goats that Jacob deceived his father (Gen 27:9); now with a young goat his sons continue the deception that dominates this family.

[37:33]  ² sn A wild animal has eaten him. Jacob draws this conclusion on his own without his sons actually having to lie with their words (see v. 20). Dipping the tunic in the goat’s blood was the only deception needed.