Chapter on the Prayer Times (Mawaqit)
Tahdhīb al-Aḥkām|Volume 2|Book 1|Chapter 13
مُحَمَّدُ بْنُ أَحْمَدَ بْنِ يَحْيَى عَنْ مُحَمَّدِ بْنِ اَلْحُسَيْنِ عَنْ مُحَمَّدِ بْنِ يَحْيَى بْنِ حَبِيبٍ قَالَ: كَتَبْتُ إِلَى أَبِي اَلْحَسَنِ اَلرِّضَا عَلَيْهِ اَلسَّلاَمُ تَكُونُ عَلَيَّ اَلصَّلاَةُ اَلنَّافِلَةُ مَتَى أَقْضِيهَا فَكَتَبَ« فِي أَيِّ سَاعَةٍ شِئْتَ مِنْ لَيْلٍ أَوْ نَهَارٍ»
Muhammad ibn Ahmad ibn Yahya narrated from Muhammad ibn Al-Husayn from Muhammad ibn Yahya ibn Habib who said:
I wrote to Abu Al-Hasan Al-Ridha, peace be upon him, asking: “The supererogatory (nafila) prayers that are due upon me, when should I make them up?” So Imam عليه السلام wrote: "At any hour you wish, whether by night or by day."
- Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 2, p. 292
- Ṣaḥīḥ al-Tahdhīb