And from him, from Hammad ibn Isa from Mu‘awiyah ibn ‘Ammar, who said:
I saw Abu Abdillah عليه السلام praying in his sandals on more than one occasion, and I never saw him remove them at all.
Ali Akbar al-Ghaffari
Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 2, p. 249