Charles Ellicott Commentary Exodus 12:5

"Your lamb shall be without blemish, a male a year old: ye shall take it from the sheep, or from the goats:" — Exodus 12:5 (ASV)

Without blemish. —Natural piety teaches that we must not offer the blind, the lame, or the sick for sacrifice (Malachi 1:8). We must give to God from our best. The Law emphasized this teaching, and here, on the first occasion when a sacrifice was formally appointed, required it to be absolutely without blemish of any kind. Afterwards the requirement was made general (Leviticus 22:19–25). It was particularly fitting that the Paschal offering should be without defect of any kind, as especially typifying the Lamb of God, who is holy, harmless, undefiled—a lamb without spot.

A male. —Males were considered superior to females and were especially appropriate here, since the victim represented the firstborn male in each house.

Of the first year —that is, not more than a year old. As children are most innocent when young, so animals too were thought to be.