Al-Husayn ibn Sa’id from Safwan from Ishaq ibn ‘Ammar, who said:
I asked Abu Ibrahim عليه السلام, peace be upon him, about a man who forgets to bow. Imam عليه السلام said: "He must begin the prayer anew until he places everything in its proper place."
Ali Akbar al-Ghaffari
Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 2, p. 158