Ishaq ibn Rahwayh was one of the leading imams.

‘Abd al-Karim ibn al-Nasa’i said: My father informed me, saying, “Ishaq is trustworthy, reliable.”

I heard Sa‘id ibn Dhu’ayb say, “I do not know anyone on the face of the earth like Ishaq.”

Abu ‘Amr Nasr ibn Zakariyya said: Ishaq ibn Ibrahim narrated to us, stating,

“Ahmad ibn Hanbal asked me about the report transmitted by al-Fadl ibn Musa from Ibn ‘Abbas:
‘The Prophet ﷺ would glance around during his prayer, yet he would not twist his neck behind his back’ (1).
I related it to him. A man then remarked, ‘Abu Ya‘qub, Waki‘ narrated it differently.’ Ahmad replied, ‘Be quiet! When Abu Ya‘qub, the Commander of the Faithful (in hadith), relates something to you, that is sufficient for you.’”

Al-Hakim transmitted this account from al-Hasan ibn Hatim al-Marwadhi, from Nasr.

Muhammad ibn Yahya ibn Khalid said: I heard Ishaq say, “I have memorised four thousand fabricated hadiths.”

Ahmad ibn Hibat Allah informed us, from ‘Abd al-Rahim ibn Abi Sa‘d; ‘Abd al-Rahman ibn ‘Abd al-Wahid, son of the master Abu’l-Qasim, informed us; my grandfather informed us (ح).

Ahmad also informed us, from Abu Ruh; Zaher informed us; Abu Ya‘la ibn al-Sabuni informed us; they said:

Abu al-Husayn al-Khaffaf told us; Abu al-‘Abbas al-Sarraj told us; Ishaq ibn Ibrahim narrated to us; ‘Abdah narrated to us; Hisham ibn ‘Urwah, from his father, from ‘A’ishah, said:

“A necklace of mine was lost, so the Messenger of Allah ﷺ sent men to search for it. When the time for prayer came they found no water and were without ablution, so they prayed without performing ablution. They reported this to the Messenger of Allah ﷺ, and Allah then revealed the verse of tayammum (dry ablution).”

Al-Bukhari also recorded it (2) through the authority of Ishaq.