'Hereby' in the Bible

And 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.

Hereby ye shall be proved: By the life of Pharaoh ye shall not go forth hence, except your youngest brother come hither.

And the man, the lord of the country, said unto us, Hereby shall I know that ye are true men; leave one of your brethren here with me, and take food for the famine of your households, and be gone: