John Gill Commentary Leviticus 5:6

"and he shall bring his trespass-offering unto Jehovah for his sin which he hath sinned, a female from the flock, a lamb or a goat, for a sin-offering; and the priest shall make atonement for him as concerning his sin." — Leviticus 5:6 (ASV)

And he shall bring his trespass offering unto the Lord, for
the sin which he has sinned
To make atonement for it; this was typical of the sacrifice of Christ, whose soul was made an offering for sin, (Mva) , "Asham" a trespass offering, (Isaiah 53:10) where the same word is used as here:

a female from the flock, a lamb, or kid of the goats, for a sin
offering ;
it is generally thought there was a difference between a trespass offering and a sin offering; but it is not easy to say where the difference lies; and what has been observed by learned men is not very satisfactory; and certain it is that the same offering is here called both a trespass offering and a sin offering; and such as were men of substance and capable of it, were to bring a female lamb or kid; it being for sins of ignorance, a sacrifice of less value was admitted; yet it must be a lamb, typical of Christ the Lamb of God; and atonement cannot be made, even for sins of ignorance, but by the blood and sacrifice of Christ:

and the priest shall make an atonement for him concerning his sin ;
that is, by offering his sacrifice for him, which was a type of the atonement made by the precious blood of Christ, as of a lamb without spot and blemish.