Numbers 8:17

17 For every first-born among the children of Israel mine, whether of man or beast: in the day in which I smote every first-born in the land of Egypt, I sanctified them to myself.

Numbers 8:17 Meaning and Commentary

Numbers 8:17

For all the firstborn of the children of Israel [are] mine,
[both] men and beasts
Not only in common with other of his creatures, but in a special respect on account of his signal deliverance of them; they were his, as Jarchi expresses it, by the line of judgment, or rule of justice and equity, because he protected them among the firstborn of the Egyptians, saved them when he slew theirs, as follows:

in the day that I smote every firstborn in the land of Egypt;
both of men and beasts:

I sanctified them for myself;
claimed them as his own, and set them apart for his own use, or ordered them to be set apart: see ( Exodus 13:2 ) .

Numbers 8:17 In-Context

15 And afterwards the Levites shall go in to perform the works of the tabernacle of witness; and thou shalt purify them, and present them before the Lord.
16 For these are given to me for a present out of the midst of the children of Israel: I have taken them to myself instead of all the first-born of the sons of Israel that open every womb.
17 For every first-born among the children of Israel mine, whether of man or beast: in the day in which I smote every first-born in the land of Egypt, I sanctified them to myself.
18 And I took the Levites in the place of every first-born among the children of Israel.
19 And I gave the Levites presented as a gift to Aaron and his sons out of the midst of the children of Israel, to do the service of the children of Israel in the tabernacle of witness, and to make atonement for the children of Israel: thus there shall be none among the sons of Israel to draw nigh to the holy things.

The Brenton translation of the Septuagint is in the public domain.