Genesis 24:13-14

13Behold, I stand [here] by the well of water, and the daughters of the men of the city come out to draw water.

14And let it come to pass, [that] the maiden to whom I shall say, Let down thy pitcher, I pray thee, that I may drink, and who will say, Drink, and I will give thy camels drink also, be she whom thou hast appointed for thy servant Isaac; and hereby I shall know that thou hast dealt kindly with my master.