Exodus 13:1

“And the Lord spake unto Moses, etc.] When he and the Israelites were at Succoth: saying; as follows.”

“THE FIRST-BORN SANCTIFIED. (Exo 13:1-2) Sanctify unto me all the first-born--To "sanctify" means to "consecrate," to "set apart" from a common to a sacred use. The foundation of this duty rested on the fact that the Israelites, having had their first-born preserved by a distinguishing act of grace from the general destruction that overtook the families of the Egyptians, were bound in token of gratitude to consider them as the Lord's peculiar property (compare Heb 12:23).”

“13:1-16 Like the Passover celebration, the practice of dedicating the firstborn memorialized what God did in the Passover event. Because he spared the firstborn, they now belonged to him and must be redeemed. The annual sacrifice and eating of the lamb symbolized what God would do in providing a substitute in his Son, Jesus Christ; we who deserve death must be redeemed with a price, the life of the Son. 13:1-10 This rehearsal of the customs surrounding Passover and the Festival of Unleavened Bread sets the stage for discussing the dedication of the firstborn (13:11-16).”

“Sanctification of the first-born, and Promulgation of the Law for the Feast of Mazzoth. - Exo 13:1, Exo 13:2. The sanctification of the first-born was closely connected with the Passover. By this the deliverance of the Israelitish first-born was effected, and the object of this deliverance was their sanctification. Because Jehovah had delivered the first-born of Israel, they were to be sanctified to Him. If the Israelites completed their communion with Jehovah in the Passover, and celebrated the commencement of their divine standing in the feast of unleavened bread, they gave uninterrupted effect to their divine sonship in the sanctification of the first-born. For this reason, probably, the…”