What is the meaning of the saying of Imam Ali, may God be pleased with him: "Three brothers from among the jinn; this is the eldest of them, the second has a large following, and the third is weak"?

Reports have been consistently transmitted confirming the killing of Ali (may Allah be pleased with him) on the Day of Nahrawan, of the man known as Al-Makhdaj or Dhul-Thudayya, whose signs and description the Prophet (peace be upon him) mentioned. Al-Makhdaj is one whose hand is incomplete, and Dhul-Thudayya because one of his upper arms was like a woman's breast.

Several hadiths hinted that he was from the jinn, but all these narrations are weak and not authenticated, with the exception of the narration of Yazid ibn Abi Salih from Abu Al-Wadi', which was described as having "extreme strangeness" or "munkar" (denounced).

The authentic and consistently transmitted narrations about the killing of Al-Makhdaj did not mention that he was from the jinn, which reinforces the weakness or denouncement of the phrases that indicate so.