John Gill Commentary Leviticus 5:18

"And he shall bring a ram without blemish out of the flock, according to thy estimation, for a trespass-offering, unto the priest; and the priest shall make atonement for him concerning the thing wherein he erred unwittingly and knew it not, and he shall be forgiven." — Leviticus 5:18 (ASV)

And he shall bring a ram without blemish out of the flock ,
&c.] (See Gill on Leviticus 5:15)

with thy estimation for a trespass [offering] to the priest ;
along with the offering was to be brought an estimate of whatsoever damage had been done through the breach of any of the commands of God, where damage could take place, that so recompense be made as before directed; or else the ram brought was to be valued, and examined whether it was worth two shekels of silver, as before explained, (See Gill on Leviticus 5:15) but no fifth was required as in the former cases:

and the priest shall make atonement for him concerning his
ignorance wherein he erred, and wist [it] not, and it shall be
forgiven him; (See Gill on Leviticus 5:10) this is what the Jews call "Asham Talui", doubtful trespass offering.