'O Lord My God' in the Bible

So now, O Lord my God, You have made Your servant king in place of David my father; and as for me, I am but a little boy [in wisdom and experience]; I do not know how to go out or come in [that is, how to conduct business as a king].

Yet graciously consider the prayer of Your servant and his supplication, O Lord my God, to listen to the [loud] 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 brought further tragedy to the widow with whom I am staying, by causing her son to die?”

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