- As for the hadith of Ibn ʿAbbās, it is narrated by Abū Yaḥyā from him:
Two men brought a dispute before the Prophet, peace and blessings be upon him. The Prophet asked the claimant for evidence, but he had no evidence. He then required the respondent to swear an oath, and he swore by Allah, besides whom there is no deity. Thereupon the Messenger of Allah said: “You did take it, but you have been forgiven because of your sincerity in saying, ‘There is no deity but Allah.’”
It was recorded by Abū Dāwūd (3275), and from him by al-Bayhaqī; and by Aḥmad (1/253, 289; 2/70), through the chain of Ḥammād ibn Salamah, from ʿAṭāʾ ibn al-Sāʾib, from Abū Yaḥyā, with this report. Abū Dāwūd then recorded it (3620), in an abbreviated form, from Abū al-Aḥwaṣ; al-Ḥākim (4/95–96), from ʿAbd al-Wārith; and Aḥmad (1/299, 322), from Sharīk—all three from ʿAṭāʾ, with it. Al-Ḥākim said: “Its chain of transmission is authentic.” Al-Dhahabī agreed with him.
I say: ʿAṭāʾ—namely, Ibn al-Sāʾib—suffered memory deterioration. In his commentary on the Musnad (4/75), Shaykh Aḥmad Shākir, may Allah have mercy on him, maintained that its chain is authentic and that Ḥammād ibn Salamah heard from ʿAṭāʾ before his memory deteriorated. The commentator on the Musnad of Abū Yaʿlā (10/56) followed him in this. However, this is countered by the fact that Ḥammād also heard from ʿAṭāʾ after his memory had deteriorated, as al-Ḥāfiẓ concluded at the end of ʿAṭāʾ’s biographical entry. Thus, judgment on it must be withheld.
Yes, Sufyān al-Thawrī also narrated it from ʿAṭāʾ—as al-Bayhaqī cited it in suspended form, while al-Nasāʾī gave it a continuous chain in the section on judicial rulings of al-Sunan al-Kubrā—through the chain of Muḥammad ibn Ismāʿīl ibn Samurah, who was trustworthy, from Wakīʿ, from Sufyān, with this report, as found in Tuḥfat al-Mizzī (4/390). Through this route, the hadith becomes authentic, for it is unanimously agreed that Sufyān al-Thawrī heard from ʿAṭāʾ before his memory deteriorated. As for Abū Yaḥyā, Abū Dāwūd said after the hadith: