عَنِ ابْنِ عَبَّاسٍ قَالَ: كَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَفْتَتِحُ صَلَاتَهُ بِ (بِسم الله الرَّحْمَن الرَّحِيم) رَوَاهُ التِّرْمِذِيُّ وَقَالَ: هَذَا حَدِيثٌ لَيْسَ إِسْنَادُهُ بِذَاكَ

Abu Zuhair an-Numairi said

We went out with God’s Messenger one night and came upon a man who made supplication with persistence. The Prophet said, “He will have done something which guarantees [paradise for him] if he puts a seal to it.” One of the people asked what he should use for a seal, and he replied, “Amen”. Abu Dawud transmitted it.