The salam to exit the prayer when one has finished and how it is done
حَدَّثَنَا زُهَيْرُ بْنُ حَرْبٍ، حَدَّثَنَا يَحْيَى بْنُ سَعِيدٍ، عَنْ شُعْبَةَ، عَنِ الْحَكَمِ، وَمَنْصُورٍ، عَنْ مُجَاهِدٍ، عَنْ أَبِي مَعْمَرٍ، أَنَّ أَمِيرًا، كَانَ بِمَكَّةَ يُسَلِّمُ تَسْلِيمَتَيْنِ فَقَالَ عَبْدُ اللَّهِ أَنَّى عَلِقَهَا قَالَ الْحَكَمُ فِي حَدِيثِهِ إِنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ يَفْعَلُهُ .
Abu Ma'mar reported: There was an Amir in Mecca who pronounced taslim twice. Abdullah said: Where did he get this sunnah? Al-Hakam said: There is a hadith to the effect that the Messenger of Allah (ﷺ) did like It.