Valmiki Ramayana Aranya Kanda Sarga 11 Shloka 57

ततः thereafter, मेषरूपिणम् assuming the form of a sheep, तं भ्रातरम् his brother, संस्कृतम् sanctified कृत्वा making, ततः then, श्राद्धदृष्टेन suitable for offering oblations to the dead, कर्मणा did, तान् द्विजान् those brahmins, भोजयामास offered them food.

Ilvala would keep his brother sanctified, so that he is fit for offering, Then he would feed the brahmins with mutton according to the rituals.