Narrated by Ahmad ibn Muhammad ibn ʿIsa, from Ali ibn al-Hakam, from Abu Ayyub, from Muhammad ibn Muslim, who said:
Abu Abdullah عليه السلام said: "Wiping of the head is to be done on its front part."
Ali Akbar al-Ghaffari
Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 1, p. 94