Sunan Abi Dawud 970
سنن أبي داود#970SahihNarrated Abdullah ibn Mas'ud: Alqamah said that Abdullah ibn Mas'ud caught hold of his hand saying that the Messenger of Allah (ﷺ) caught hold of his (Ibn Mas'ud's) hand and taught him the tashahhud during prayer. He then narrated the (well known ) tradition (of tashahhud). This version adds: When you say this or finish this, then you have completed your prayer. If you want to stand up, then stand, and if you want to remain sitting, then remain sitting
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniShadh
Muhammad Muhyi Al-Din Abdul HamidShadh
Zubair Ali ZaiIsnaad Sahih
In-book reference: 2:581