The Prophet ﷺ used to point with his finger (at the end of the tashahhud) and he would not move it. Ibn Juraij said: "And 'Amr bin Dinar added: 'He (Ziyad) said: "'Amir informed me from his father that he saw the Prophet ﷺ supplicating like that. And the Prophet ﷺ would brace himself with his left hand on his left knee. (Using translation from Abū Dāʾūd 989)
أَنَّ النَّبِيَّ ﷺ كَانَ يُشِيرُ بِأُصْبُعِهِ إِذَا دَعَا لَا يُحَرِّكُهَا قَالَ ابْنُ جُرَيْجٍ وَرَأَيْتُ عَمْرَو بْنَ دِينَارٍ قَالَ أَخْبَرَنِي عَامِرٌ عَنْ أَبِيهِ أَنَّهُ رَأَى النَّبِيَّ ﷺ يَدْعُو كَذَلِكَ يَتَحَامَلُ النَّبِيُّ ﷺ بِيَدِهِ الْيُسْرَى عَلَى رِجْلِهِ الْيُسْرَى عَلَى فَخِذِهِ وَكَذَلِكَ