A captive whose help the polytheists seek in fighting other polytheists

Imam al-Shafi'i (may Allah have mercy on him) said: "It has been said that he may fight them, (because) Sayyiduna al-Zubayr (may Allah be pleased with him) and some of his companions fought in the land of Abyssinia on behalf of polytheists against (other) polytheists. And if someone were to say that he should refrain from fighting them for the reasons that Imam al-Shafi'i (may Allah have mercy on him) mentioned, that too would be a (valid) position. And we do not know the report about Sayyiduna al-Zubayr (may Allah be pleased with him) to be established; and even if it were established, the Negus was a Muslim: he had believed in the Messenger of Allah (peace and blessings be upon him), and the Prophet (peace and blessings be upon him) offered the funeral prayer for him."

Abu Bakr bin Abd al-Rahman bin al-Harith bin Hisham narrates from Sayyidah Umm Salamah (may Allah be pleased with her) that when the land of Makkah became constricted for us, then she mentioned the account of their emigration to Abyssinia, and of Quraysh sending Amr bin al-As and Abdullah bin Abi Rabi'ah to the Negus so that he would expel the Muslims from his country and return them to them, and of Sayyiduna Ja'far bin Abi Talib (may Allah be pleased with him) and his other companions going in to the Negus. The Negus asked: Do you have with you anything of what that Prophet has brought? Sayyiduna Ja'far (may Allah be pleased with him) said: Yes, and recited to him the opening verses of Surah Maryam. Then the Negus wept until his beard was soaked, and his bishops wept until their scriptures were soaked. He said: This speech comes from the very same place from which (revelation) came to Sayyiduna Musa (peace be upon him). Go, rightly guided. Then she mentioned what the two (envoys of Quraysh) presented to the Negus: that these people say Sayyiduna Isa bin Maryam (peace be upon him) is a servant. So the Companions (may Allah be pleased with them) went in to the Negus while his patriarchs were with him, and he asked: What do you say about Sayyiduna Isa bin Maryam (peace be upon him)? Sayyiduna Ja'far (may Allah be pleased with him) said: We say that he is the servant of Allah and His Messenger, and His word and His spirit, which Allah cast to the chaste virgin Sayyidah Maryam (may Allah be pleased with her). The Negus lowered his hand to the ground, took a small twig between his two fingers and said: Sayyiduna Isa bin Maryam (peace be upon him) did not go beyond what you have said by even this twig. Then she mentioned the hadith. Sayyidah Umm Salamah (may Allah be pleased with her) says: It was not long before a man from Abyssinia rose against him, contesting his kingship. By Allah, we never felt a grief more severe than that, fearing that the other king would overcome him and that a king would come who did not recognise our rights as this one did. We supplicated to Allah and kept seeking His help for the Negus. The Negus marched out against him, and the Companions (may Allah be pleased with them) said to one another: Who will go and be present at the battle to see what happens? Sayyiduna al-Zubayr (may Allah be pleased with him) volunteered; he was still a young man. They filled a waterskin with air for Sayyiduna al-Zubayr (may Allah be pleased with him), which he placed under his chest, and swimming on it he crossed the Nile and reached the other side where the fighting was taking place. The battle took place, and Allah defeated that king and he was killed. The Negus was granted victory, and Sayyiduna al-Zubayr (may Allah be pleased with him) informed us by waving his cloak. He was saying: Allah has granted victory to the Negus. And we rejoiced greatly at the victory of the Negus.