مِشْكَاةُ الْمَصَابِيحِ
Mishkat al-Masabih 661
Prayer
The Excellence of the Adhan and the Response to the Mu’adhdhin - Section 1
وَعَنْ سَعْدِ بْنِ أَبِي وَقَّاصٍ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ أَنَّهُ قَالَ: «مَنْ قَالَ حِينَ يَسْمَعُ الْمُؤَذِّنَ أَشْهَدُ أَنْ لَا إِلَهَ إِلَّا اللَّهُ وَحْدَهُ لَا شَرِيكَ لَهُ وَأَنَّ مُحَمَّدًا عَبْدُهُ وَرَسُولُهُ رَضِيتُ بِاللَّهِ رَبًّا وَبِمُحَمَّدٍ رَسُولًا وَبِالْإِسْلَامِ دِينًا غُفِرَ لَهُ ذَنبه» . رَوَاهُ مُسلم
Sa‘d b. Abu Waqqas reported God’s Messenger as saying: If anyone says when he hears the mu’adhdhin, “I testify that there is no god but God alone who has no partner and that Muhammad is His servant and Messenger; I am satisfied with God as Lord, with Muhammad as Messenger, and with Islam as religion,” his sins will be forgiven him. Muslim transmitted it.
Mishkat al-Masabih, 661صَحِيح (الألباني)