The Dislike of Sleeping After the Fajr Prayer
Man Lā Yaḥḍuruh al-Faqīh|Volume 1|Book 1|Chapter 78
وَ رُوِيَ: «قِيلُوا فَإِنَّ اَللَّهَ يُطْعِمُ اَلصَّائِمَ فِي مَنَامِهِ وَ يَسْقِيهِ.
It is narrated: "Take a midday nap (Qailulah), for indeed Allah سبحانه وتعالى nourishes and provides drink to the fasting person during their sleep."
- Ṣaḥīḥ al-Faqīh