Al-Matalib al-'Aliyah 2505 — Cauterisation

It is narrated from al-Ala bin Ziyad (may Allah have mercy on him) that a woman came to the Prophet (peace and blessings be upon him) with her son, whose belly had swollen (from the disease of dropsy). She submitted: "O Messenger of Allah! My son is afflicted with this illness that you see; shall I cauterise him with fire?" He (peace and blessings be upon him) said: "Do not cauterise your son." The woman firmly resolved that she would not cauterise him. Then (by chance) a camel stumbled and fell on the child, or struck him hard (trampled him), so that his belly burst open and he recovered. The woman came again to the Messenger of Allah (peace and blessings be upon him) and submitted: "O Messenger of Allah! May my father and mother be sacrificed for you! I asked your permission to cauterise my son but you stopped me; then a camel passed by him and struck him or trampled him, so that his belly burst open, and now he is cured." The Prophet (peace and blessings be upon him) said: "Take note! Had I given you permission (to cauterise), you would surely have thought that it was the fire that cured him."
This narration is found in Musnad al-Harith (Zawa'id al-Haythami); however, since al-Ala bin Ziyad is a Successor, this narration is mursal (with the Companion omitted).