Through this chain of narration, from Muhammad ibn Ya’qub, from Ali ibn Ibrahim, from his father, from Ibn Abi Umayr, from Hammad ibn Uthman, from al-Halabi, who said: I asked Abu Abdullah عليه السلام about someone engaging in non-penetrative sexual activity (mufakhadhah). Is ghusl required? Imam عليه السلام said: "Yes, if ejaculation occurs."