وَعَنْ عَوْنِ بْنِ عَبْدِ اللَّهِ عَنِ ابْنِ مَسْعُودٍ
قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «إِذَا رَكَعَ أَحَدُكُمْ فَقَالَ فِي رُكُوعِهِ: سُبْحَانَ رَبِّيَ الْعَظِيمِ ثَلَاثَ مَرَّاتٍ فَقَدْ تَمَّ رُكُوعُهُ وَذَلِكَ أَدْنَاهُ وَإِذَا سَجَدَ فَقَالَ فِي سُجُودِهِ سُبْحَانَ رَبِّيَ الْأَعْلَى ثَلَاثَ مَرَّاتٍ فَقَدْ تَمَّ سُجُودُهُ وَذَلِكَ أَدْنَاهُ»
When one of you bows and says three times while doing so, “Glory be to my mighty Lord”, his bowing is complete; and that is the least which effects this. When he prostrates himself and says three times while doing so, “Glory be to my most high Lord”, his prostration is complete; and that is the least which effects this.
Mishkat al-Masabih 826, Book 5, Prayer, Hadith 304. 1 min read