Greeting (prayers upon entering the masjid) while the Imam is preaching Sahih Muslim 875 e
Arabic hadith text
حَدَّثَنَا مُحَمَّدُ بْنُ بَشَّارٍ، حَدَّثَنَا مُحَمَّدٌ، - وَهُوَ ابْنُ جَعْفَرٍ - حَدَّثَنَا شُعْبَةُ، عَنْ عَمْرٍو، قَالَ سَمِعْتُ جَابِرَ بْنَ عَبْدِ اللَّهِ، أَنَّ النَّبِيَّ صلى الله عليه وسلم خَطَبَ فَقَالَ "إِذَا جَاءَ أَحَدُكُمْ يَوْمَ الْجُمُعَةِ وَقَدْ خَرَجَ الإِمَامُ فَلْيُصَلِّ رَكْعَتَيْنِ "
Translation
Jabir b. 'Abdullah said that the Messenger of Allah (ﷺ) delivered the sermon and said
When any one of you comes for the Friday (prayer) and the Imam comes out (from his apartment), (even then) should observe two rak'ahs (of prayer).