From him, from his father, from Hammad, from Hariz, from one who mentioned it, from Abu Ja’far عليه السلام, peace be upon him:
Imam al-Baqir عليه السلام saw no problem with a person praying while walking, as he is walking. But he should not be driving the camels.
Ali Akbar al-Ghaffari
Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 3, p. 252