We used to salute during prayer and talk about our needs. I came to the Messenger of Allah ﷺ and found him praying. I saluted him, but he did not respond to me. I recalled what happened to me in the past and in the present. When the Messenger of Allah ﷺ finished his prayer, he said to me: Allah, the Almighty, creates new command as He wishes, and Allah, the Exalted, has sent a fresh command that you must not talk during prayer. He then returned my salutation. (Using translation from Abū Dāʾūd 924)   

كُنَّا نُسَلِّمُ فِي الصَّلَاةِ وَنَأْمُرُ بِحَاجَتِنَا فَقَدِمْتُ عَلَى رَسُولِ اللهِ ﷺ وَهُوَ يُصَلِّي فَسَلَّمْتُ عَلَيْهِ فَلَمْ يَرُدَّ عَلَيَّ السَّلَامَ فَأَخَذَنِي مَا قَدُمَ وَمَا حَدُثَ فَلَمَّا قَضَى رَسُولُ اللهِ ﷺ الصَّلَاةَ قَالَ إِنَّ اللهَ يُحْدِثُ مِنْ أَمْرِهِ مَا يَشَاءُ وَإِنَّ اللهَ قَدْ أَحْدَثَ أَنْ لَا تَكَلَّمُوا فِي الصَّلَاةِ فَرَدَّ عَلَيَّ السَّلَامَ