Chapter on Times of Prayer and Sign of Each of Its Times

And what was narrated with this chain from al-Hasan ibn Ali ibn Faddal from Tha’labah ibn Maymun from ‘Ubaydullah and ‘Imran, the two sons of Ali al-Halabi, who said: We used to argue on the road about the prayer, the ‘Ishaʾ al-Akhirah, before the disappearance of the shafaq, and some among us would feel uneasy about that. So we entered upon Abu Abdillah عليه السلام and asked him about performing the ‘Ishaʾ al-Akhirah before the disappearance of the Shafaq. Imam عليه السلام said: "There is no problem with that." We asked: "And what is the shafaq?" Imam عليه السلام said: "The redness."