Majma al-Zawaid — Hadith 13938

Sayyiduna Zayd bin Thabit (may Allah be pleased with him) says: I used to write down the revelation for the Prophet (peace and blessings be upon him). When revelation came down upon him, a severe trembling would overtake him and he would sweat profusely, the sweat being like pearls. Then, when this state passed from him, I would take a piece of wood or a fragment and write the revelation on it while he dictated it. Once, during such a state (his thigh was on my leg), my leg was about to break from the weight of the Qur'an, until I thought that I would never be able to walk on this leg again. When this state ended, the Prophet (peace and blessings be upon him) said: Read it! I read it, and whatever mistake there was in it, he would have it corrected. Then I would take it out to the people.
Al-Tabarani recorded it with two chains; the narrators of one of them are thiqat (trustworthy).