Parashas Chayei Sarah · Passuk 24:14
let the maiden to whom I say, ‘Please, lower your jar that I may drink,’ and who replies, ‘Drink, and I will also water your camels’—let her be the one whom You have decreed for Your servant Yitzchak. Thereby shall I know that You have dealt graciously with my master.
Torah Temimah points to Berachos / related (priority of feeding animals).
TT lemma: שתה וגם גמליך.
Sefaria — Berachos 40a (related)
English: From here [we learn] that although it is forbidden for a person to taste food before feeding his animal, that applies to eating; but regarding drinking, the person takes precedence, as we find with Rivkah who said “Drink, and I will also water your camels.”
Custom (Bavli — priority of human drinking vs. animal feeding)
A person may drink before watering animals, even though one must feed animals before eating oneself; Rivkah’s offer of water first to the man and then to the camels supports the distinction.