Genesis 24:13-14

13Behold, I am standing by the fountain of water; and the daughters of the men of the city are coming out to draw water: 14and let it come to pass, that the damsel to whom I shall say, Let down thy pitcher, I pray thee, that I may drink; and she shall say, Drink, and I will give thy camels drink also: let the same be she that thou hast appointed for thy servant Isaac; and thereby shall I know that thou hast showed kindness unto my master.