ויקרא ו,ב: זֹאת תּוֹרַת הָּעֹלָּה הִוא הָּעֹלָּה
The Sforno explains that there are three parts of the burnt offering (עולה) the disposition of which are indicated in these verses. The principal part is that which is totally consumed and goes up, hence the term עולה, literally going up.
The second part consists of the ashes which still retain some fat of the animal and are burnt together with the first part. Thus, the words את העולה (verse 3) are to be translated “with the olah.”
The third part consists of the ashes carried out of the camp by the Kohen after he changed his regular priestly garments for clothes of lessor quality, since he is now occupied with a non-holy duty. Nonetheless, the ashes are treated with respect and placed in a מקום טהר (a clean place).
