'God of Heaven' in the Bible

Then, after hearing these words, for some days I gave myself up to weeping and sorrow, seated on the earth; and taking no food I made prayer to the God of heaven,

And said, O Lord, the God of heaven, the great God, greatly to be feared, keeping faith and mercy with those who have love for him and are true to his laws:

Then the king said to me, What is your desire? So I made prayer to the God of heaven.

Then answering them I said, The God of heaven, he will be our help; so we his servants will go on with our building: but you have no part or right or any name in Jerusalem.