'Mayest' in the Bible

so that thou mayest not appear fasting unto men, but to thy Father who is in secret; and thy Father who sees in secret shall render it to thee.

And a scribe came up and said to him, Teacher, I will follow thee whithersoever thou mayest go.

And I will give to thee the keys of the kingdom of the heavens; and whatsoever thou mayest bind upon the earth shall be bound in the heavens; and whatsoever thou mayest loose on the earth shall be loosed in the heavens.