ואת כל חלבו וגו'. עַד כָּאן לֹא נִתְפָּרְשׁוּ אֵמוּרִין בָּאָשָׁם, לְכָךְ הֻצְרַךְ לְפָרְשָׁם כָּאן, אֲבָל חַטָּאת כְּבָר נִתְפָּרֵשׁ בָּהּ בְּפָרָשַׁת וַיִּקְרָא: ואת 'כל חלבו וגו [HE SHALL OFFER OF IT] ALL THE FAT etc. — So far the fat portions of the guilt offering that have to be offered have not yet been mentioned as having to be burnt (though the אשם itself has already been dealt with in Leviticus 5:15), Scripture therefore was compelled expressly to specify them here. So far, however, as the sin-offering is concerned, it (the burning of their fat) has already been mentioned in the Sedrah ויקרא (Leviticus ch. 4), therefore it was unnecessary to mention it in 6:18—23.
את האליה. לְפִי שֶׁאָשָׁם אֵינוֹ בָּא אֶלָּא אַיִל אוֹ כֶּבֶשׂ, וְאַיִל וְכֶבֶשׂ נִתְרַבּוּ בְּאַלְיָה: את האליה THE FAT TAIL — Because only a ram or a lamb can be offered as a guilt-offering and the altar’s share in the case of a ram and lamb has been augmented by the fat tail (cf. Leviticus 3:9), therefore it is here naturally mentioned as having to be burnt.