Sahih Bukhari · Hadith 5100

حدثنا عمرو بن عاصم، حدثنا همام، عن قتادة، قال سئل أنس كيف كانت قراءة النبي صلى الله عليه وسلم‏.‏ فقال كانت مدا‏.‏ ثم قرأ بسم الله الرحمن الرحيم، يمد ببسم الله، ويمد بالرحمن، ويمد بالرحيم‏.‏

Narrated Qatada: Anas was asked, "How was the recitation (of the Qur'an) of the Prophet?' He replied, "It was characterized by the prolongation of certain sounds." He then recited: In the Name of Allah, the Most Beneficent, the Most Merciful prolonging the pronunciation of 'In the Name of Allah, 'the most Beneficent,' and 'the Most Merciful.

Gradings are classical jarḥ-wa-taʿdīl, name-matched to a rijāl index (not individually re-verified).