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 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 water thy camels also: let the same be she that thou hast appointed for thy servant Isaac; and by that shall I know that thou hast shown kindness to my master.