Mishkat al-Masabih 9 Supplications كتاب الدعوات 72

وَعَنْهُ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: ” كَلِمَتَانِ خَفِيفَتَانِ عَلَى اللِّسَانِ ثَقِيلَتَانِ فِي الْمِيزَانِ حَبِيبَتَانِ إِلَى الرَّحْمَنِ: سُبْحَانَهُ الله وَبِحَمْدِهِ سُبْحَانَهُ الله الْعَظِيم ”

He reported God’s messenger as saying, “Two expressions which are light on the tongue but heavy in the scale are dear to the Compassionate One: Glory be to God, and I begin with praise of Him; and Glory be to God the Incomparably Great.” (Bukhari and Muslim.)