Exodus 13:1-2

"And Jehovah spake unto Moses, saying, Sanctify unto me all the first-born, whatsoever openeth the womb among the children of Israel, both of man and of beast: it is mine."

There were three great memorials of the deliverance of Israel from Egyptian bondage, namely: (1) The Passover; (2) The Feast of Unleavened Bread; and (3) the Sanctification of the First-born. Each of these was uniquely associated with the event of the deliverance and is incapable of being intelligently associated with anything else. The Passover stressed God's PASSING OVER the houses of the Israelites on that fatal night; the Unleavened Bread recalled the HASTE OF THEIR DEPARTURE and the unavailability of any leaven during those stressful days; the Sanctification of the First-born was a PERPETUAL REMINDER that only the first-born were slain. This triple memorial, continuously observed throughout historic times establishes without question the historicity of the tremendous event memorialized.

These memorials also did something else. They established an unending chain of teaching and instruction designed to keep God's people informed throughout all subsequent ages with reference to the events memorialized and their significance to the children of Israel, and unto all people.

Apparently, the reason for the third of these memorials being mentioned in these two verses ahead of the second (the unleavened bread) was that of firmly identifying the third as connected and unified with the other two.

As to when the instructions in the chapter were given, "They were probably given to Moses on the very day of the setting forth and, most likely, at Succoth."[1]

This setting apart of the first-born was not designed to separate a priesthood, or anything like that, but was actually a representative thing signifying that "all Israel" was holy unto the Lord. "Inasmuch as the first birth represented all the births, the whole nation was to consecrate itself unto Jehovah, and present itself as a priestly nation in the consecration of the first-born."[2] All Israel were intended to be priests unto God, as indeed came to be the case during Messiah's times and the New Israel of God, which is the church. Although so intended even for the Old Israel, this situation, due to the weakness and unwillingness of Israel, was altered, leading to the substitution of the Levitical order of the priesthood for the whole nation.

The triple memorial of Passover, Unleavened Bread, and Consecration of the First-born was far more than mere symbols or memorials. "They (all three) were to be vivid visual aids by which the older generation would instruct the younger in the ways of God."[3] Furthermore, this was designed to continue from generation to generation throughout the ages (See Exodus 13:8-10).