四分律比丘含注戒本 3.19

3.19

(If one eats without rebuking her, an offense is committed mouthful by mouthful. For a bhikṣuṇī, a duṣkṛta. There is no offense if one says: "Elder sister, wait a moment; wait until all the bhikṣus have finished eating"; if the bhikṣuṇī is herself the donor; if the donor prepares the meal and orders the bhikṣuṇī to arrange it; or if she does not intentionally show bias toward one or the other, there is no offense.)