Majma al-Zawaid — Hadith 2596

Sayyiduna Uqbah bin Amir al-Juhani (may Allah be pleased with him) said: For every gesture that a man makes with his hand during his prayer, a reward is recorded: for each finger he receives one good deed (the narrator is unsure; perhaps the words are:) one rank is granted.
Al-Tabarani recorded it, and its chain is hasan (good).