Parashas Chayei Sarah · Passuk 24:19
When she had let him drink his fill, she said, “I will also draw for your camels, until they finish drinking.”
Rashi on Bereishis 24:19 (classical source on this passuk; not listed as a numbered Torah Temimah unit here).
Lemma / focus: עד אם כלו.
English: Here “im” functions in the sense of “that”: until they have finished drinking their fill—that is the completion of their drinking, when they have drunk enough.
Derash on the verse (Rashi) — not a formal named middah of the 13: the particle is fixed by parallel usage, and the offer itself completes the sign.
Rivkah offers of her own accord to draw for the camels until they have drunk their fill; the second half of Eliezer’s sign is fulfilled by her initiative.