Sahih Muslim Book 4, Hadith Number 967.

Chapter : Moderation in the articles of prayers and their shortening and perfection.

Abu Sa’id al-Khudri reported: When the Messenger of Allah (may peace be upon him) raised his head after bowing, he said: O Allah! our Lord, to Thee be the praise that would fill all the heavens and the earth, and all that it pleases Thee besides (them). O, thou art worthy of praise and glory, most worthy of what a servant says, and we all are Thy servants, no one can withhold what Thou givest or give what Thou withholdest, and riches cannot avail a wealthy person against Thee.