'O God' in the Bible

Then you will go on further from there, and you will come to the terebinth tree of Tabor, and three men going up to [sacrifice to] God at Bethel will meet you there, one carrying three young goats, another carrying three loaves of bread, and another carrying a jug of wine.

Then Samuel told the people the requirements of the kingdom, and wrote them in a book and placed it before the Lord. And Samuel sent all the people away, each one to his home.

Then Saul said, “Let us go down after the Philistines by night and plunder them until the morning light, and let us not leave a man of them [alive].” They said, “Do whatever seems good to you.” Then the priest said, “Let us approach God here.”