John Gill Commentary Leviticus 7:18

"And if any of the flesh of the sacrifice of his peace-offerings be eaten on the third day, it shall not be accepted, neither shall it be imputed unto him that offereth it: it shall be an abomination, and the soul that eateth of it shall bear his iniquity." — Leviticus 7:18 (ASV)

And if any of the flesh of his peace offerings be eaten at
all on the third day
Any part of it, even the least:

it shall not be accepted ;
as a sacrifice well pleasing to God; he will take no delight in it, or express any satisfaction therein; but, on the contrary, reject it with abhorrence:

neither shall it be imputed to him that offereth it ;
the Targum of Jonathan adds, for merit or righteousness; it shall not be accounted a righteous action, or the offerer receive any benefit by it:

it shall be an abomination ;
to God, the flesh being kept so long, through a sordid and niggardly disposition:

and the soul that eateth of it shall bear his iniquity ;
it shall not be forgiven him; he shall bear the punishment of it.