وَعَن أبي زُهَيْر النميري قَالَ: خَرَجْنَا مَعَ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ ذَاتِ يَوْمٍ فَأَتَيْنَا عَلَى رَجُلٍ قَدْ أَلَحَّ فِي الْمَسْأَلَةِ فَقَالَ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ:
أَوْجَبَ إِنْ خَتَمَ ". فَقَالَ: رَجُلٌ مِنَ الْقَوْمِ: بِأَيِّ شَيْءٍ يَخْتِمُ؟ قَالَ: «بآمين» . رَوَاهُ أَبُو دَاوُد
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 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.
Source: Mishkat al-Masabih — repository translation · Al-Khatib Al-Tabrizi — authenticity/grade metadata requires independent source review · Sunnah.comAudio not available for the selected reciter.
Source: Mishkat al-Masabih — repository arabic · Al-Khatib Al-Tabrizi · Sunnah.com