en_tn_condensed/exo/17/16.md

a hand was lifted up

People would raise their hand when they made a promise or pledge, so raising the hand represents making a promise. AT: "a promise was made" (See: rc://en/ta/man/translate/figs-metonymy)

a hand was lifted up

This can be stated in active form. AT: "Yahweh lifted up his hand" or "Yahweh made a solemn promise" (See: rc://en/ta/man/translate/figs-activepassive)