Sunan Ibn Majah Book 5, Hadith 109
“I
saw the Prophet (ﷺ) putting his right hand on his right thigh
during prayer, and pointing with his finger.”
“The Messenger of Allah (ﷺ) said to a man: ‘What do you say during your Salat?’ He said: ‘The Tashah-hud, then I ask Allah for Paradise, and I seek refuge with Him from Hell, but I do not understand what you and Mu’adh murmur (during Salat). He said: ‘Our murmuring revolves around the same things.’”
“I saw the Prophet (ﷺ) making a circle with his thumb and middle finger, and raising the one next to it (the index finger), supplicating with it during the Tashah-hud.”