Because all the first borne are mine: for on the day that I smote all the first borne in the land of Egypt, I halowed vnto mee all the first borne in Israel, both man, and beast, mine they shall be: I am the Lord.
- King James Version (1611) - View 1611 Bible Scan

"For all the firstborn are Mine; on the day that I struck down all the firstborn in the land of Egypt, I sanctified to Myself all the firstborn in Israel, from man to beast. They shall be Mine; I am the LORD."
- New American Standard Version (1995)

for all the first-born are mine; on the day that I smote all the first-born in the land of Egypt I hallowed unto me all the first-born in Israel, both man and beast; mine they shall be: I am Jehovah.
- American Standard Version (1901)

For all the first sons are mine; on the day when I put to death all the first sons in the land of Egypt, I took for myself every first male birth of man and beast. They are mine; I am the Lord.
- Basic English Bible

for every firstborn is mine. On the day that I smote all the firstborn in the land of Egypt, I hallowed unto me all the firstborn in Israel, both of man and beast; mine shall they be: I am Jehovah.
- Darby Bible

Because all the first-born are mine; for on the day that I smote all the first-born in the land of Egypt, I hallowed to me all the first-born in Israel, both man and beast: mine they shall be: I am the LORD.
- Webster's Bible

for all the firstborn are mine. On the day that I struck down all the firstborn in the land of Egypt I made holy to me all the firstborn in Israel, both man and animal. They shall be mine. I am Yahweh."
- World English Bible

for Mine [is] every first-born, in the day of My smiting every first-born in the land of Egypt I have sanctified to Myself every first-born in Israel, from man unto beast; Mine they are; I [am] Jehovah.'
- Youngs Literal Bible

for all the first-born are Mine: on the day that I smote all the first-born in the land of Egypt I hallowed unto Me all the first-born in Israel, both man and beast, Mine they shall be: I am the LORD.'
- Jewish Publication Society Bible

Wesley's Notes for Numbers 3:13

3:12 The first - born - Who were God's property, #Exo 13:12|, and to whom the administration of holy things was formerly committed, which now was taken away from them, either because they had forfeited this privilege by joining with the rest of their brethren in the idolatrous worship of the calf, or because they were to be mainly concerned in the distribution and management of the inheritances which now they were going to possess, and therefore could not be at leisure to attend upon the service of the sanctuary: and God would not commit it to some other persons in each tribe, which might be an occasion of idolatry, confusion, division, and contempt of sacred things, but to one distinct tribe, which might be entirely devoted to that service, and particularly to the tribe of Levi; partly out of his respect to Moses and Aaron, branches of this tribe; partly as a recompence of their zeal for God against idolaters, and partly because it was the smallest of the tribes, and therefore most likely to find both employment in, and maintenance for the work.

3:15 From a month old - Because at that time the first - born, in whose stead the Levites came, were offered to God. And from that time the Levites were consecrated to God, and were, as soon as capable, instructed in their work. Elsewhere they are numbered from twenty - five years old, when they were entered as novices into part of their work, #Num 8:24|, and from thirty years old, when they were admitted to their whole office.