'Lo' in the Bible

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

And, lo, Zadok also came , and all the Levites 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 Jehovah when he saw the angel that smote the people, and said, Lo, I have sinned, and I have done perversely; but these sheep, what have they done? let thy hand, I pray thee, be against me, and against my father's house.