I saw the Prophet ﷺ placing his right hand on his right thigh during the prayer and pointing with his finger.
حدثنا أبو بكر بن أبي شيبة حدثنا وكيع عن عصام بن قدامة
رأيت النبي ﷺ واضعا يده اليمنى على فخذه اليمنى في الصلاة ويشير بإصبعه
[Its isnad is hasan] Abu Dawud narrated it, Prayer, chapter on gesturing during tashahhud, no. 991, from the hadith of Isam through him, and Ibn Khuzayma and Ibn Hibban graded it sahih. Malik bin Numayr was deemed reliable by Ibn Khuzayma and Ibn Hibban.