Sayyiduna Abu Umamah (may Allah be pleased with him) said: The Prophet (peace and blessings be upon him) saw me moving my lips and said: "O Abu Umamah! What are you saying?" I said: I am remembering Allah. He said: "Shall I not tell you of something that is greater (in weight) than your remembering Allah night and day? Say: All praise is for Allah, equal to the number of what He has created; all praise is for Allah, filling what He has created; all praise is for Allah, equal to the number of what is in the heavens and what is in the earth; all praise is for Allah, equal to the number of what His Book has recorded; all praise is for Allah, filling what His Book has recorded; all praise is for Allah, equal to the number of all things; all praise is for Allah, filling all things. And glorify Allah in the same way." Then he said: "Teach these words to your descendants after you."
Hadith Referenceالمعجم الكبير للطبراني / باب الصاد / 7899