(1) The report comes from Abdullah ibn Masud. It is recorded by Abu Dawud (1/157); al-Nasai (1/194-195); al-Tirmidhi (2/89); Ibn Majah (1/295); al-Daraqutni (p. 136); al-Tahawi (1/158); al-Tabarani in al-Kabir (3/67/2); al-Bayhaqi (2/177); and Ahmad (1/390, 406, 408, 409, 444, 448). It is also in the Musannaf of Abd al-Razzaq (2/219) and the Musnad of Abu Ya‘la (3/1252 = 9/40/5102). All of these chains pass through Abu Ishaq from Abu al-Ahwas—some narrators further add al-Aswad ibn Yazid and Alqama—all reporting from Ibn Masud. Al-Tirmidhi, who omits the added names, graded the hadith “hasan sahih” (good and sound). Al-Nasai, al-Daraqutni, al-Tahawi, al-Bayhaqi, and Ahmad (1/394, 418) also transmit it through Israil and Zuhayr, both from Abu Ishaq, from Abd al-Rahman ibn al-Aswad, from his father—some likewise add Alqama—from Ibn Masud, with the extra wording: “I saw Abu Bakr and Umar do the same.” Al-Daraqutni judged this chain stronger than the first. Further versions are given by al-Daraqutni, al-Bayhaqi, and Ahmad (1/409, 414, 438) through other lines of transmission. The core wording is found in Sahih Muslim (2/91), al-Nasai, al-Darimi (1/310-311), and al-Bayhaqi. The late shaykh also cites it in his work al-Sifa, printed within al-Tabarani’s al-Awsat (1/2600/2).