صَحِيحُ مُسْلِمٍ
Sahih Muslim 596 a
The Book of Mosques and Places of Prayer
It is recommended to recite statements of remembrance after the prayer, and how that is to be done
وَحَدَّثَنَا الْحَسَنُ بْنُ عِيسَى، أَخْبَرَنَا ابْنُ الْمُبَارَكِ، أَخْبَرَنَا مَالِكُ بْنُ مِغْوَلٍ، قَالَ سَمِعْتُ الْحَكَمَ بْنَ عُتَيْبَةَ، يُحَدِّثُ عَنْ عَبْدِ الرَّحْمَنِ بْنِ أَبِي لَيْلَى، عَنْ كَعْبِ بْنِ عُجْرَةَ، عَنْ رَسُولِ اللَّهِ صلى الله عليه وسلم قَالَ مُعَقِّبَاتٌ لاَ يَخِيبُ قَائِلُهُنَّ - أَوْ فَاعِلُهُنَّ - دُبُرَ كُلِّ صَلاَةٍ مَكْتُوبَةٍ ثَلاَثٌ وَثَلاَثُونَ تَسْبِيحَةً وَثَلاَثٌ وَثَلاَثُونَ تَحْمِيدَةً وَأَرْبَعٌ وَثَلاَثُونَ تَكْبِيرَةً .
Ka'b b. 'Ujra reported Allah's Messenger (ﷺ) as saying: There are certain ejaculations, the repeaters of which or the performers of which after every prescribed prayer will never be caused disappointment:" Glory be to Allah" thirty-three times." Praise be to Allah" thirty-three times, and" Allah is most Great" thirty-four times.
Sahih Muslim, 596 aSahihصحيح