Coverings for Sin.

“And the eyes of them both were opened, and they knew that they were naked; and they sewed fig leaves together, and made themselves aprons” (Gen 3:7).

“Unto Adam also and to his wife did the LORD God make coats of skins, and clothed them” (v. 21).

. . .

“And in process of time it came to pass, that Cain brought of the fruit of the ground an offering unto the LORD.
“And Abel, he also brought of the firstlings of his flock and of the fat thereof. And the LORD had respect unto Abel and to his offering:
“But unto Cain and to his offering he had not respect. And Cain was very wroth, and his countenance fell” (4:3-5).