Abbas transmitted—on the authority of Yahya ibn Maʿin—that he said:
“Zakariyya ibn Abi Zaʿidah, Zuhayr, and Israʾil: their reports from Abu Ishaq are almost on the same level; the true companions of Abu Ishaq are Sufyan and Shuʿbah.”

Abbas al-Duri said: Hujayn ibn al-Muthanna narrated to us:
“When Israʾil came to Baghdad, people gathered around him. He was seated on an elevated platform. A man stood beside him holding a notebook and began asking him questions from it while the crowd could not see what was in it. When Israʾil rose to leave, that man sat down and dictated the notebook to the people.” (1)

ʿAbd al-Rahman ibn Mahdi used to say, “In his narrations from Abu Ishaq, Israʾil is more reliable than Shuʿbah and al-Thawri.”

I say: Of the opinions mentioned earlier, this is the one to which I am most inclined. Israʾil was like his grandfather’s walking stick—always at his side—and, along with his knowledge and prodigious memory, he was a man of integrity and humility. His brother ʿIsa, however, was even more precise, more knowledgeable, and more devout.

Abu Ahmad ibn ʿAdi devoted a lengthy entry to him (2) and listed a number of rare narrations.

It has reached us from Shaqiq al-Balkhi, who said:
“I learned humility from Israʾil. We would sit around him and he would not know who was on his right or who was on his left because of his deep contemplation of the Hereafter. I realized then that he was a righteous man.”

ʿAli ibn al-Madini related that Yahya al-Qattan said, “Israʾil ranks above Abu Bakr ibn ʿAyyash.”

Someone said to Yahya, “But Israʾil narrated three hundred reports from Ibrahim ibn Muhajir and three hundred from Abu Yahya al-Qattat!”
He replied, “The error does not come from him; it comes entirely from those two.” (3)