This verse says essentially the same thing about the fellowship offering (peace offering) as is said in the previous verses about the whole burnt offering.

A sacrifice of peace offerings: that is, “a fellowship offering.” See chapter 3.

To fulfil a vow: this is not the same expression as translated “in payment of a vow” in verse 18. The exact meaning of the Hebrew word translated to fulfil is uncertain. Some take it to mean “explicit” (New Jerusalem Bible) or “special” (New English Bible, New American Standard Bible, An American Translation). But the majority of versions understand it as containing the idea of fulfillment (Revised Standard Version and Good News Translation).

From the herd or from the flock: see 1.2.

Perfect: the Hebrew word used here really means “complete, whole, sound, unimpaired.” In this context it is the opposite of “defective” and is thus virtually synonymous with the expression that follows, there shall be no blemish in it. Good News Translation renders the two expressions together as “must be without any defects.”

Quoted with permission from Péter-Contesse, René and Ellington, John. A Handbook on Leviticus. (UBS Helps for Translators). New York: UBS, 1990. For this and other handbooks for translators see here .