Leviticus 5:12

Then shall he bring it to the priest
The flour just as it was, not kneaded and made into a cake, as appears by what follows:

and the priest shall take his handful of it;
as much of the flour as he could hold in one hand:

[even] a memorial thereof;
to bring to mind his sin, and the goodness of God in admitting of an offering for it, and forgiving it upon that:

and burn [it] on the altar, according to the offerings made by fire
unto the Lord;
in the same manner as other burnt offerings were made:

it [is] a sin [offering];
or an expiatory sacrifice for sin.