سُبْحَانَ اللهِ وَبِحَمْدِهِ ، عَدَدَ خَلْقِهِ ، وَرِضَا نَفْسِهِ ، وَزِنَةَ عَرْشِهِ وَمِدَادَ كَلِمَاتِهِ

 

Translation:: Glory be to Allah and with His praise(equal to) the magnitude of His Creation and (equal to)pleasure of His self, and (equal to) the weight of His Throne, and (equal to) the ink of His words. (3 times in the morning)
Reference: Muslim

 

Background:: Once the Prophet(pbuh) was going for Fajr prayers, and he saw Juwairiya(ra) praying. When he came back from prayers, around the time of Chaasht prayers (a little before Zuhr prayers) he saw Juwairiya(ra) still at her prayer mat, Prophet(pbuh) then taught her this dua and explained to her that these four clauses are greater in weight than what she had been praying all morning.