Chapter on Times of Prayer and Sign of Each of Its Times
Tahdhīb al-Aḥkām|Volume 2|Book 1|Chapter 4
وَرَوَى اَلْحُسَيْنُ بْنُ سَعِيدٍ عَنِ اَلنَّضْرِ وَفَضَالَةَ عَنِ اِبْنِ سِنَانٍ عَنْ أَبِي عَبْدِ اَللَّهِ عَلَيْهِ اَلسَّلاَمُ قَالَ:« لِكُلِّ صَلاَةٍ وَقْتَانِ وَ أَوَّلُ اَلْوَقْتَيْنِ أَفْضَلُهُمَا وَقْتُ صَلاَةِ اَلْفَجْرِ حِينَ يَنْشَقُّ اَلْفَجْرُ إِلَى أَنْ يَتَجَلَّلَ اَلصُّبْحُ اَلسَّمَاءَ وَ لاَ يَنْبَغِي تَأْخِيرُ ذَلِكَ عَمْداً لَكِنَّهُ وَقْتُ مَنْ شُغِلَ أَوْ نَسِيَ أَوْ سَهَا أَوْ نَامَ وَ وَقْتُ اَلْمَغْرِبِ حِينَ تَجِبُ اَلشَّمْسُ إِلَى أَنْ تَشْتَبِكَ اَلنُّجُومُ وَ لَيْسَ لِأَحَدٍ أَنْ يَجْعَلَ آخِرَ اَلْوَقْتَيْنِ وَقْتاً إِلاَّ مِنْ عُذْرٍ أَوْ عِلَّةٍ»
Narrated by al-Husayn ibn Sa’id from al-Nadr and Fadalah from Ibn Sinan:
Abu Abdillah عليه السلام said: "For every prayer there are two times, and the first of the two is the better. The time of the Fajr prayer is from the moment the dawn splits until the morning light covers the sky, and it is not appropriate to delay that deliberately, but it is the time for one who is preoccupied, forgets, is heedless, or sleeps. And the time of Maghrib is from the setting of the sun until the stars become interwoven. And no one should make the latter of the two times their time (of prayer), except due to an excuse or a valid reason."
- Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 2, p. 41
- Ṣaḥīḥ al-Tahdhīb, p. 156