Sahih al-Bukhari 4645
In-book no 4645حَدَّثَنَا آدَمُ، حَدَّثَنَا وَرْقَاءُ، عَنِ ابْنِ أَبِي نَجِيحٍ، عَنْ مُجَاهِدٍ، قَالَ ابْنُ عَبَّاسٍ أَمَرَهُ أَنْ يُسَبِّحَ، فِي أَدْبَارِ الصَّلَوَاتِ كُلِّهَا. يَعْنِي قَوْلَهُ {وَأَدْبَارَ السُّجُودِ}
Narrated Mujahid: Ibn `Abbas said, "Allah ordered His Prophet to celebrate Allah's praises after all prayers." He refers to His Statement: 'After the prayers.' (50.40)