'Lo' in the Bible

And the young man that told him said, As I happened by chance upon mount Gilboa, behold, Saul leaned upon his spear; and, lo, the chariots and horsemen followed hard after him.

And lo Zadok also, and all the Levites were with him, bearing the ark of the covenant of God: and they set down the ark of God; and Abiathar went up, until all the people had done passing out of the city.

And David spake unto the LORD when he saw the angel that smote the people, and said, Lo, I have sinned, and I have done wickedly: but these sheep, what have they done? let thine hand, I pray thee, be against me, and against my father's house.