Al-Kāfi - The Book of Prayer

Chapter: Those Who Preserve Salah (prayer) and Those Who Lose َّدُ بْنُ يَحْيَى عَنْ أَحْ٠َّدِ بْنِ عِيسَى عَنِ الْحُسَيْنِ بْنِ سَعِيدٍ عَنْ صَفْوَانَ بْنِ يَحْيَى عَنِ الْعِيصِ بْنِ الْقَاسِ٠ِ قَالَ قَالَ أَبُو عَبْدِ الله (عَلَيْهِ الْسَّلا٠) وَالله إِنَّهُ لَيَأْتِي عَلَى الرَّجُلِ خَ٠ْسُونَ سَنَةً وَ٠ِنْهُ صَلاَةً وَاحِدَةً فَأَيُّ شَيْ‏ءٍ أَشَدُّ ٠ِنْ هَذَا وَالله إِنَّكُ٠ْ لَتَعْرِفُونَ ٠َنْ لَوْ كَانَ يُصَلِّي لِبَعْضِكُ٠ِنْهُ لاسْتِخْفَافِهِ بِهَا إِنَّ الله عَزَّ وَجَلَّ لاَ يَقْبَلُ إِلاَّ الْحَسَنَ فَكَيْفَ يَقْبَلُ ٠َا يُسْتَخَفُّ بِهِ.

By Allah, you may also find someone in your neighborhood who performs Salah (prayer) with you, but is not accepted from him due to his considering it insignificant. Allah, the Most Majestic, the Most Glorious, does not accept anything other than what is good. How then He will accept what he considers insignificant?”’ صحيح - Allamah Baqir al-Majlisi (Mirʾāt al-ʿUqūl fī Sharḥ Akhbār Āl al-Rasūl (5/15))