The flour of a sin offering can be simply compared to the animal sin-offering. Just as the animal sin-offering becomes invalid with the wrong intent - and this was the first rule in the laws of animal sacrifices - so too the flour of the sin-offering. However, what can be said of the flour of jealousy? - Both are connected to "iniquity." About the flour of jealousies it says, "reminder of iniquity," and about the sin-offering it is written, "and it He gave to you to gain forgiveness for the iniquity." Thus, by the method of "the same word," or "gezeirah shavah" we can say that the flour of jealousies becomes completely invalid if the kohen takes a handful of it to be burned for the sake of another offering.
Art: Lorenzo Lotto - Husband And Wife 1523