'Separating' in the Bible

then ye have prepared a fire-offering to Jehovah, a burnt-offering, or a sacrifice, at separating a vow or free-will-offering, or in your appointed things, to make a sweet fragrance to Jehovah, out of the herd, or out of the flock.

'And when thou makest a son of the herd a burnt-offering or a sacrifice, at separating a vow or peace-offerings to Jehovah,