לא תאפה חמץ חלקם. אַף הַשְּׁיָרִים אֲסוּרִים בְּחָמֵץ (מנחות נ"ה): לא תאפה חמץ חלקם IT SHALL NOT BE BAKEN AS ANYTHING LEAVENED FOR THEIR PORTION — The remains of the meal-offering which become the portion of the priests, are also forbidden to be baked in the form of leavened (Menachot 55a).
כחטאת וכאשם. מִנְחַת חוֹטֵא הֲרֵי הִיא כְּחַטָּאת, לְפִיכָךְ קְמָצָהּ שֶׁלֹא לִשְׁמָהּ פְּסוּלָה, מִנְחַת נְדָבָה הֲרֵי הִיא כְּאָשָׁם, לְפִיכָךְ קְמָצָהּ שֶׁלֹּא לִשְׁמָהּ כְּשֵׁרָה (ספרא): כחטאת וכאשם [IT IS MOST HOLY] AS THE SIN OFFERING OR THE GUILT OFFERING — the meal-offering of the sinner (v. 11) is as the sin-offering, therefore if he (the priest) takes the fistful out of it not as such (not having in mind that offering) it is invalid as is the sin-offering under such circumstances (cf. Rashi on 5:12); a free-will meal-offering (i.e. any of the other meal-offerings mentioned in ויקרא), however, is as the guilt-offering, therefore if he takes the fistful out of it not doing it as such, it is still valid (Sifra, Tzav, Chapter 3 3; Zevachim 11a).