Ahmad ibn Muhammad from Abdurrahman ibn Abi Najran from Safwan Al-Jammal, who said:
I saw Abu Abdillah عليه السلام, in the howdah prostrating upon paper, and most of the time Imam عليه السلام would gesture with a slight indication.
Ali Akbar al-Ghaffari
Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 2, p. 333