The Chapter on the Virtues of Prayer
Man Lā Yaḥḍuruh al-Faqīh|Volume 1|Book 1|Chapter 31
وَقَالَ اَلصَّادِقُ عَلَيْهِ اَلسَّلاَمُ: «إِنَّ طَاعَةَ اَللَّهِ عَزَّ وَ جَلَّ خِدْمَتُهُ فِي اَلْأَرْضِ وَ لَيْسَ شَيْءٌ مِنْ خِدْمَتِهِ يَعْدِلُ اَلصَّلاَةَ فَمِنْ ثَمَّ نَادَتِ اَلْمَلاَئِكَةُ زَكَرِيَّا عَلَيْهِ اَلسَّلاَمُ « وَ هُوَ قٰائِمٌ يُصَلِّي فِي اَلْمِحْرٰابِ »
Imam Jafar ibn Muhammad Al-Sadiq عليه السلام said: "Obedience to Allah سبحانه وتعالى, the Mighty and Majestic, is to serve Him on earth, and there is nothing among His acts of service that equals prayer. This is why the angels called out to Zakariya عليه السلام 'while he was standing in prayer in the sanctuary' (Surah Ale ‘Imran 3:39)”.
- Ṣaḥīḥ al-Faqīh