Mishkat al-Masabih #2094
The Excellent Qualities of the Qur'an
The Arabic includes the chain of narration (sanad) and the collector's commentary; the English translation shows the Prophet's words only.
وَعَنْ قَتَادَةَ قَالَ: سُئِلَ أَنَسٌ: كَيْفَ كَانَتْ قِرَاءَةُ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فَقَالَ: كَانَت مدا مَدًّا ثُمَّ قَرَأَ: بِسْمِ اللَّهِ الرَّحْمَنِ الرَّحِيمِ يَمُدُّ بِبَسْمِ اللَّهِ وَيَمُدُّ بِالرَّحْمَنِ وَيَمُدُّ بِالرَّحِيمِ. رَوَاهُ البُخَارِيّ
Qatādā said that when Anas was asked how the Prophet recited the Qur’ān he replied that he did so prolonging the words. Then he recited “In the name of God, the Compassionate, the Merciful,” prolonging each phrase.
Bukhārī transmitted it.
About Mishkat al-Masabih
This hadith is #2094 from Mishkat al-Masabih, in the Book of The Excellent Qualities of the Qur'an.