Chapter on Miscellaneous Matters
Man Lā Yaḥḍuruh al-Faqīh|Volume 3|Book 3|Chapter 45
وَ قَالَ عَلِيٌّ عَلَيْهِ اَلسَّلاَمُ: "يُسْتَحَبُّ لِلرَّجُلِ أَنْ يَأْتِيَ أَهْلَهُ أَوَّلَ لَيْلَةٍ مِنْ شَهْرِ رَمَضَانَ لِقَوْلِ اَللَّهِ عَزَّ وَ جَلَّ: أُحِلَّ لَكُمْ لَيْلَةَ اَلصِّيٰامِ اَلرَّفَثُ إِلىٰ نِسٰائِكُمْ وَ اَلرَّفَثُ اَلْمُجَامَعَةُ".
Imam Ali ibn Abi Talib عليه السلام said: "It is recommended for a man to approach his wife on the first night of the month of Ramadan because of the saying of Allah سبحانه وتعالى, the Mighty and Majestic: 'It has been made lawful for you to be intimate with your wives during the nights of fasting' (Surah Al-Baqarah 2:187), and al-rafath means sexual intercourse."
- Ṣaḥīḥ al-Faqīh, p. 290