Leviticus 3:7

If he offer a lamb for his offering,.... Which was of the flock, and must be of the first year; this is a rule laid down by Maimonides i, that where ever this word is used in the law, it signifies one of the first year:

then shall he offer it before the Lord; bring it into the court, and present it to the priest.

i Maaseh Hakorbanot, c. 1. sect. 14.