Midrash Tanchuma Beresheet on the Order of Creation

"Rabbi Yitzchak said: When a mortal builds a palace, be begins building from the bottom and then builds the upper part. But, the Holy One, Blessed Is He, first built the upper part and then He built the lower part, as it is stated, 'In the beginning of God's creating the heaven', and then afterward, 'and the earth'."

-- Midrash Tanchuma, Beresheet §4