When the Messenger of Allah (ﷺ) sat during the prayer, he put his hands on his knees and raised the finger that is next to the thumb, and supplicates with it, and his left hand was on his knee laid on it.
Sunan an-Nasa'i Book 13, Hadith 91
← Previous Hadith "I am going to watch the Messenger of Allah (ﷺ) and see how he prays. So, I watched him." And he described (his prayer): "Then he sat and lay his left foot on the ground, and placed his left hand on his left thigh and knee. He put his right elbow on his right thigh, then he made a circle with two fingers of his (right) hand, then he raised his finger and I saw him moving it, supplicating with it."

Sunan an-Nasa'i Book 13, Hadith 90 Next Hadith → That the Prophet (ﷺ) used to point with his finger when he supplicated, but he did not move it. Ibn Jurayj said: "And 'Amr added: 'Amir bin 'Abdullah bin Az-Zubair told me that his father saw the Prophet (ﷺ) supplicating like that, putting his weight on his left arm, leaning on his left leg.'"

Sunan an-Nasa'i Book 13, Hadith 92