The Chapter on Obligatory Prayers
Man Lā Yaḥḍuruh al-Faqīh|Volume 1|Book 1|Chapter 30
وَقَالَ زُرَارَةُ وَ اَلْفُضَيْلُ: قُلْنَا لِأَبِي جَعْفَرٍ عَلَيْهِ اَلسَّلاَمُ أَ رَأَيْتَ قَوْلَ اَللَّهِ عَزَّ وَ جَلَّ: « إِنَّ اَلصَّلاٰةَ كٰانَتْ عَلَى اَلْمُؤْمِنِينَ كِتٰاباً مَوْقُوتاً » قَالَ «يَعْنِي كِتَاباً مَفْرُوضاً وَ لَيْسَ يَعْنِي وَقْتَ فَوْتِهَا إِنْ جَازَ ذَلِكَ اَلْوَقْتَ ثُمَّ صَلاَّهَا لَمْ تَكُنْ صَلاَةً مُؤَدَّاةً وَ لَوْ كَانَ ذَلِكَ كَذَلِكَ لَهَلَكَ سُلَيْمَانُ بْنُ دَاوُدَ عَلَيْهِ اَلسَّلاَمُ حِينَ صَلاَّهَا بِغَيْرِ وَقْتِهَا وَ لَكِنَّهُ مَتَى مَا ذَكَرَهَا صَلاَّهَا.
Zurarah and Al-Fudail said: "We asked Abu Ja'far (Imam al-Baqir عليه السلام) about the statement of Allah سبحانه وتعالى, the Mighty Majestic: 'Indeed, prayer has been decreed upon the believers a timed decree' (Surah An-Nisa 4:103). Imam عليه السلام replied: "It means that it is an obligatory decree (prescribed prayer) and does not refer to a specific cut-off time after which it would not be valid. If one misses the prescribed time and then performs the prayer, it would not be considered a timely (adā') prayer. If this were so, then Sulayman ibn Dawud (Solomon عليه السلام) would have been destroyed when he prayed outside its prescribed time, but rather, whenever he remembered it, he performed it."
- Ṣaḥīḥ al-Faqīh