'Mayest' in the Bible

Only Jehovah give thee discretion and understanding, and give thee charge concerning Israel; that so thou mayest keep the law of Jehovah thy God.

Now, behold, in my affliction I have prepared for the house of Jehovah a hundred thousand talents of gold, and a thousand thousand talents of silver, and of brass and iron without weight; for it is in abundance: timber also and stone have I prepared; and thou mayest add thereto.