Ahmad ibn Muhammad narrated from Muhammad ibn Sinan, from Abu Khalid, from Abu Hamzah:
Abu Ja'far عليه السلام said: "A man should not wash a woman unless no other woman is available."
Ali Akbar al-Ghaffari
Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 1, p. 465