Say three times -

سُبْحَانَ اللَّهِ وَبِحَمْدِهِ عَدَدَ خَلْقِهِ وَرِضَى نَفْسِهِ وَزِنَةَ عَرْشِهِ وَمِدَادَ كَلِمَاتِهِ

SubhaanAllahi wa bihamdihi, 'Adada khalqihi, wa ridhaa nafsihi, wa zinata 'arshihi wa midaada kalimaatihi.

How perfect Allah is! I praise Him by the number of His creation and His pleasure, and by the weight of His throne, and the ink of His words. Juwairiya reported that Allah's Messenger (ﷺ) came out from (her apartment) in the morning as she was busy in observing her dawn prayer in her place of worship. He came back in the forenoon and she was still sitting there. He (the Holy Prophet) said to her: You have been in the same seat since I left you. She said: Yes. Thereupon Allah's Apostle (ﷺ) said: I recited four words (above mentioned words) three times after I left you and if these are to be weighed against what you have recited since morning these would outweigh them.

Reference: Muslim: 2726