Moses
Exodus 34:19BSB·traditional attribution

The first offspring of every womb belongs to Me, including all the firstborn males among your livestock, whether cattle or sheep.

John Calvin Reformed @genevareformer

19. All that openeth the matrix is mine. He here defines what the offering was to be, viz., that they should redeem their children as well as the unclean animals at a price; but that they should bring into the tabernacle whatsoever could be offered in sacrifice.

Matthew Henry Presbyterian @wholebiblehenry

Here is a repetition of several appointments made before, especially relating to their solemn feasts. When they had made the calf, they proclaimed a feast in honour of it; now, that they might never do so again, they are here charged with the observance of the feasts which God had instituted.

Commenting on Exodus 34:18-27

John Gill Reformed Baptist @doctorgill

Six days shalt thou work, but on the seventh day thou shalt rest,.... This is the law of the seventh day sabbath, which is after repeated, to fix it in the minds and memories of the people, see Exo 20:10 and here it is added, which has not been mentioned before: in earing and in harvest thou shall rest; that is, in the time of...