As for what was narrated by Al-Saffar from Muhammad bin Isa, who said:
(Narrator said) "A man wrote to Imam عليه السلام asking: 'Is it obligatory to perform wudu for what exits from the penis after istibra?' Imam عليه السلام wrote: 'Yes.'"
Ali Akbar al-Ghaffari
Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 1, p. 29