سَأَلَ مُحَمَّدُ بْنُ مُسْلِمٍ أَبَا جَعْفَرٍ ع عَنِ الرَّجُلِ يُسَلِّمُ عَلَى الْقَوْمِ
Hadith.1063 - Muhammad ibn Muslim asked Imam Muhammad ibn Ali Al-Baqir (as) about a person who greets others while in prayer. Imam (as) said: "If a Muslim greets you while you are in prayer, respond to him by saying, ‘As-salamu ‘alayka,' and gesture with your finger."