'O Lord My God' in the Bible

Now, O Lord my God, You have made Your servant king in place of my father David, yet I am but a little child; I do not know how to go out or come in.

Yet have regard to the prayer of Your servant and to his supplication, O Lord my God, to listen to the cry and to the prayer which Your servant prays before You today;

He called to the Lord and said, “O Lord my God, have You also brought calamity to the widow with whom I am staying, by causing her son to die?”

Then he stretched himself upon the child three times, and called to the Lord and said, “O Lord my God, I pray You, let this child’s life return to him.”