The Chapter on the Virtues of Prayer
Man Lā Yaḥḍuruh al-Faqīh|Volume 1|Book 1|Chapter 31
وَقَالَ عَلَيْهِ اَلسَّلاَمُ: «إِيَّاكُمْ وَ اَلْكَسَلَ فَإِنَّ رَبَّكُمْ رَحِيمٌ يَشْكُرُ اَلْقَلِيلَ إِنَّ اَلرَّجُلَ لَيُصَلِّي اَلرَّكْعَتَيْنِ يُرِيدُ بِهِمَا وَجْهَ اَللَّهِ تَعَالَى فَيُدْخِلُهُ اَللَّهُ بِهِمَا اَلْجَنَّةَ وَ إِنَّهُ لَيَتَصَدَّقُ بِدِرْهَمٍ تَطَوُّعاً يُرِيدُ بِهِ وَجْهَ اَللَّهِ عَزَّ وَ جَلَّ فَيُدْخِلُهُ اَللَّهُ بِهِ اَلْجَنَّةَ وَ إِنَّهُ لَيَصُومُ اَلْيَوْمَ تَطَوُّعاً يُرِيدُ بِهِ وَجْهَ اَللَّهِ عَزَّ وَ جَلَّ فَيُدْخِلُهُ اَللَّهُ بِهِ اَلْجَنَّةَ.
Imam عليه السلام said: "Beware of laziness, for your Lord عز وجل is Merciful and appreciates even the smallest acts. Indeed, a person may pray two rak'ahs (units of prayer) sincerely seeking the Face of Allah سبحانه وتعالى (The Aimmah عليه السلام), and Allah سبحانه وتعالى will admit him into Paradise because of them. And indeed, a person may give a single dirham in charity with sincerity, seeking the Face of Allah سبحانه وتعالى, and Allah سبحانه وتعالى will admit him into Paradise because of it. And indeed, a person may fast one day as a voluntary act, sincerely seeking the Face of Allah سبحانه وتعالى, and Allah سبحانه وتعالى will admit him into Paradise because of it."
- Ṣaḥīḥ al-Faqīh