'Firstlings' in the Bible

And Abel, he also brought of the firstlings of his flock and of the fat thereof. And Jehovah had respect unto Abel and to his offering:

All that openeth the womb is mine; and all thy cattle that is male, the firstlings of cow and sheep.

And thou shalt take the Levites for me (I am Jehovah) instead of all the first-born among the children of Israel; and the cattle of the Levites instead of all the firstlings among the cattle of the children of Israel:

and thither ye shall bring your burnt-offerings, and your sacrifices, and your tithes, and the heave-offering of your hand, and your vows, and your freewill-offerings, and the firstlings of your herd and of your flock:

Thou mayest not eat within thy gates the tithe of thy grain, or of thy new wine, or of thine oil, or the firstlings of thy herd or of thy flock, nor any of thy vows which thou vowest, nor thy freewill-offerings, nor the heave-offering of thy hand;

And thou shalt eat before Jehovah thy God, in the place which he shall choose, to cause his name to dwell there, the tithe of thy grain, of thy new wine, and of thine oil, and the firstlings of thy herd and of thy flock; that thou mayest learn to fear Jehovah thy God always.

also the first-born of our sons, and of our cattle, as it is written in the law, and the firstlings of our herds and of our flocks, to bring to the house of our God, unto the priests that minister in the house of our God;