So it shall serve as a sign on your hand and a symbol on your forehead, for with a mighty hand the LORD brought us out of Egypt.”
Here we have, I. Further directions concerning the dedicating of their firstborn to God. 1. The firstlings of their cattle were to be dedicated to God, as part of their possessions. Those of clean beasts - calves, lambs, and kids - if males, were to be sacrificed, Exo 22:30; Num 18:17, Num 18:18.
Commenting on Exodus 13:11-16
And it shall be for a token upon thine head, and for frontlets between thine eyes,.... These laws observed concerning the setting apart the firstlings of their beasts, the redemption of the firstborn of unclean ones, and of the firstborn of men, will bring the reason of it, the destruction of the firstborn of Egypt, and the preservation of the firstborn of Israel, as fresh...
It shall be for a token, etc. - See Clarke's note on Exo 13:9.