Genesis 4:3-5

Cain and Abel

³ In the course of time Cain brought to the Lord an offering of _u the fruit of the ground, ⁴ and Abel also brought of _v the firstborn of his flock and of their fat portions. And the Lord _w had regard for Abel and his offering, ⁵ but _x for Cain and his offering he had no regard. So Cain was very angry, and his face fell.

1. Cross References
   Leviticus 2:12
   As an offering of firstfruits you may bring them to the Lord, but they shall not be offered on the altar for a pleasing aroma.
   Numbers 18:12
   All the best of the oil and all the best of the wine and of the grain, the firstfruits of what they give to the Lord, I give to you.
   
2. Cross References
   Exodus 13:12
   You shall set apart to the Lord all that first opens the womb. All the firstborn of your animals that are males shall be the Lord 's.
   Numbers 18:17
   But the firstborn of a cow, or the firstborn of a sheep, or the firstborn of a goat, you shall not redeem; they are holy. You shall sprinkle their blood on the altar and shall burn their fat as a food offering, with a pleasing aroma to the Lord.
   Proverbs 3:9
   Honor the Lord with your wealth and with the firstfruits of all your produce.
   
3. Cross References
   Hebrews 11:4
   By faith Abel offered to God a more acceptable sacrifice than Cain, through which he was commended as righteous, God commending him by accepting his gifts. And through his faith, though he died, he still speaks.
   
4. Cross References
   Proverbs 21:27
   The sacrifice of the wicked is an abomination; how much more when he brings it with evil intent.