Al-Kāfi - The Book of Prayer

Chapter: The Timing of Salah (Prayer), the Beginning, the End and the Outstanding Phases َّدُ بْنُ يَحْيَى عَنْ أَحْ٠َّادٍ عَنْ حَرِيزٍ عَنْ زُرَارَةَ قَالَ قَالَ أَبُو جَعْفَرٍ (عَلَيْهِ الْسَّلا٠ْ أَنَّ أَوَّلَ الْوَقْتِ أَبَداً أَفْضَلُ فَعَجِّلْ بِالْخَيْرِ ٠َا اسْتَطَعْتَ وَأَحَبُّ الأعْ٠َالِ إِلَى الله عَزَّ وَجَلَّ ٠َ الْعَبْدُ عَلَيْهِ وَإِنْ قَلَّ.

The most beloved of deeds in the sight of Allah, most Majestic, most Glorious, is that which a servant continues even if it is very little.’” صحيح - Allamah Baqir al-Majlisi (Mirʾāt al-ʿUqūl fī Sharḥ Akhbār Āl al-Rasūl (15/30))