"I prayed with the Messenger of Allah ﷺ and when we said the salam we used to gesture with our hands: 'Asalamu alaykum wa rahmatullah (peace be upon, peace be upon you).' The Messenger of Allah ﷺ looked at us and said: 'What is the matter with you, pointing with your hands as if they are the tails of wild horses? When any one of you says the salam, let him turn to his companions and not gesture with his hand.'" (Using translation from Nasāʾī 1326)
صَلَّيْتُ مَعَ رَسُولِ اللهِ ﷺ فَكُنَّا إِذَا سَلَّمْنَا أَشَرْنَا بِأَيْدِينَا السَّلَامُ عَلَيْكُمْ فَنَظَرَ إِلَيْنَا رَسُولُ اللهِ ﷺ فَقَالَ «مَا شَأْنُكُمْ تُشِيرُونَ بِأَيْدِيكُمْ كَأَنَّهَا أَذْنَابُ خَيْلٍ شُمُسٍ إِذَا سَلَّمَ أَحَدُكُمْ فَلْيَلْتَفِتْ إِلَى أَصْحَابِهِ وَلَا يُومِئْ بِيَدِهِ»