كتاب الصلاة
2  
The Book on Salat (Prayer)
(42)
Chapter: [What Has Been Related About] What Supplications Is Said [By A Muslim] When The Mu'adh-dhin Calls The Adhan
(42)
باب مَا جَاءَ مَا يَقُولُ الرَّجُلُ إِذَا أَذَّنَ الْمُؤَذِّنُ مِنَ الدُّعَاءِ
Jami` at-Tirmidhi 210
Sa'd bin Abi Waqqas narrated that :
Allah's Messenger said: "Whoever says, when he hears the Mu'adh-dhin: (Wa Ana Ashadu An La Ilaha Illallah, Wahdahu La Sharika Lahu, Wa Anna Muhammadan Abduhu Wa Rasuluhu, Radittu Billahi Rabban Wa Bil-Islam Dinan, Wa Bi Muhammadin Rasulan) 'I too testify that none has the right to be worshiped but Allah, Alone without partners, and that Muhammad is His slave and Messenger, I am pleased with Allah as my Lord, with Islam as my religion and Muhammad as a Messenger.' - Allah will pardon his sins for him."
حَدَّثَنَا قُتَيْبَةُ، حَدَّثَنَا اللَّيْثُ، عَنِ الْحُكَيْمِ بْنِ عَبْدِ اللَّهِ بْنِ قَيْسٍ، عَنْ عَامِرِ بْنِ سَعْدٍ، عَنْ سَعْدِ بْنِ أَبِي وَقَّاصٍ، عَنْ رَسُولِ اللَّهِ صلى الله عليه وسلم قَالَ ‏ "‏ مَنْ قَالَ حِينَ يَسْمَعُ الْمُؤَذِّنَ وَأَنَا أَشْهَدُ أَنْ لاَ إِلَهَ إِلاَّ اللَّهُ وَحْدَهُ لاَ شَرِيكَ لَهُ وَأَنَّ مُحَمَّدًا عَبْدُهُ وَرَسُولُهُ رَضِيتُ بِاللَّهِ رَبًّا وَبِمُحَمَّدٍ رَسُولاً وَبِالإِسْلاَمِ دِينًا غُفِرَ لَهُ ذَنْبُهُ ‏"‏ ‏.‏ قَالَ أَبُو عِيسَى وَهَذَا حَدِيثٌ حَسَنٌ صَحِيحٌ غَرِيبٌ لاَ نَعْرِفُهُ إِلاَّ مِنْ حَدِيثِ اللَّيْثِ بْنِ سَعْدٍ عَنْ حُكَيْمِ بْنِ عَبْدِ اللَّهِ بْنِ قَيْسٍ ‏.‏
Grade: Sahih (Darussalam)
Reference : Jami` at-Tirmidhi 210
In-book reference : Book 2, Hadith 62
English translation : Vol. 1, Book 2, Hadith 210