Greeting the Worshipper
Man Lā Yaḥḍuruh al-Faqīh|Volume 1|Book 1|Chapter 52
وَ رَوَى عَنْهُ مَنْصُورُ بْنُ حَازِمٍ أَنَّهُ قَالَ: «إِذَا سُلِّمَ عَلَى اَلرَّجُلِ وَ هُوَ يُصَلِّي يَرُدُّ عَلَيْهِ خَفِيّاً كَمَا قَالَ.
Mansur ibn Hazim narrated from Imam عليه السلام that He said: "If someone greets a man while he is praying, he should respond to him quietly, as He (the greeter) said."
- Ṣaḥīḥ al-Faqīh