Zaid b. Arqam said ; One of us used to speak to the man standing by his side during prayer. Then the Quranic verse “ And stand up with devotion to Allah”  

كَانَ أَحَدُنَا يُكَلِّمُ الرَّجُلَ إِلَى جَنْبِهِ فِي الصَّلاَةِ فَنَزَلَتْ { وَقُومُوا لِلَّهِ قَانِتِينَ } فَأُمِرْنَا بِالسُّكُوتِ وَنُهِينَا عَنِ الْكَلاَمِ