It is stated in "AlMughny" (vol. 8, pp. 414415): "It is not permissible to seek the help of the Mushriks." Ibn AlMundhir, AlJawzajany, and a group of scholars held the same opinion. However, Ahmad recorded a Hadith which indicates the permissibility of seeking their help. AlKhiraqy is of the opinion that it is permissible to seek their help when necessary. This is also the opinion of AlShafi`y for the Hadith which was narrated by AlZuhry as mentioned above and the narration of the Hadith of Safwan ibn Umayyah. The Mushrik whose help is sought must have a good opinion with regard to the Muslims; otherwise it is not permissible to seek his help. Since the help of an untrustworthy Muslim, like one who weakens the morale of the Muslims and spreads rumors to dishearten them, is forbidden to be sought, the help of the disbeliever is also forbidden to be sought in this case.
This view is supported by what is narrated by `Aishah (may Allah be pleased with her), who said, The Messenger of Allah (peace be upon him) set out for Badr and when he reached Harrah AlWabarah, a Mushrik (one who associates others with Allah in His Divinity or worship) who is known for his valor and courage met him. The Mushrik said, "I have come to follow you and take a share from the booty." The Prophet (peace be upon him) asked him, "Do you believe in Allah and His Messenger?" The man replied, "No." The Prophet said, "Go back for I will not seek the help of a Mushrik." The Messenger of Allah (peace be upon him) went on and when we reached AlBaida', the man met him again and repeated his request. The Messenger of Allah (peace be upon him) repeated the question to him, "Do you believe in Allah and His Messenger?" The man replied, "Yes." The Messenger of Allah (peace be upon him) said to him, "Then come along with us." (Related by AlBukhari, Muslim, and AlJawzajany)
It is recorded by Imam Ahmad on the authority of `AbdulRahman ibn Khubayb who said: A man from my tribe and I came to the Messenger of Allah (peace be upon him). I told him, "O Messenger of Allah! We feel ashamed that our people will fight in a battle and we will not take part with them." The Prophet (peace be upon them) asked, "Did you embrace Islam?" We replied, "No." He (peace be upon him) said, "We do not seek the help of the Mushriks against Mushriks." Ibn AlMundhir stated that the Hadith, which indicates that the Prophet (peace be upon him) sought their help is not authentic. [End of quotation].
After he quoted the Hadith related to the permissibility and the impermissibility of seeking the help of the Mushriks, AlHafizh said in his book, "AlTalkhis": The common ground between the Hadith of `Aishah, the Hadith of Safwan ibn Umayyah, and the Hadith Mursal (a Hadith with no Companion of the Prophet in the chain of narration) of AlZuhry are represented in the following points which were transmitted by AlBayhaqy from Al Shafi`y: First, the Prophet (peace be upon him) felt that the man would embrace Islam so he sent him back hoping that he would accept Islam and he was correct. However, this view is questionable bearing in mind that the wording of the Hadith indicates generality, in the form of a negated indefinite expression. Second, it might mean that the matter should be referred to the Imam; however, this view is also questionable. Third, it might also mean that seeking the help of Mushriks was initially prohibited but this prohibition was later lifted by a concession; this opinion is the closest to correctness, and it was adopted by AlShafi`y.
It is stated in "AlFuru`" (vol. 6, pp. 4950) "Seeking the help of the Mushriks is Makruh unless necessary." A group of scholars said, "It is permissible when necessary to seek the help of the Mushrik who can be trusted with the Muslim's affairs." He added in AlMuharir, "When his power depends on the enemy."
AlSan`any (may Allah be pleased with him) said in his book Subul AlSalam (vol. 4, pp. 4950) in his explanation of the Hadith narrated by `Aishah (may Allah be pleased with her), "Go back for I will not seek the help of a Mushrik," "According to a group of scholars, this Hadith indicates that it is not permissible to seek the help of Mushrik in fighting." However,
AlHadwiyyah, Abu Hanifah and his followers believe that this matter is permissible because the Prophet (peace be upon him) sought the help of Safwan ibn Umayyah in the Battle of Hunayn, and he also sought the help of the Jews of Banu Qaynuqa` and agreed on their opinion.This was recorded by Abu Dawud, and AlTirmidhyon the authority of AlZuhry as a Hadith Mursal. However, the Hadith Mursal which are narrated by AlZuhry are Da`if (a Hadith that fails to reach the status of Hasan, due to a weakness in the chain of narration or one of the narrators). AlDhahaby said: Because he used to make mistakes and so the Hadith which he narrates contain doubtful matters and Tadlis (misrepresentation resulting from a Hadith narrator who provides misleading information about his shaykh or the chain of narration). AlBayhaqy recorded on the authority of Abu Hamid Al Sa`idy that the Prophet (peace be upon him) sent the Mushriks back.
The compiler said: The different narrations can be reconciled by the assumption that the Prophet (peace be upon him) sent back the Mushrik on the Battle of Badr, because he (peace be upon him) felt that he would embrace Islam; so he sent him back hoping that he would accept Islam and he was correct. It might also mean that seeking the help of Mushriks is prohibited but the Prophet (peace be upon him) gave Rukhsah (concession) and this opinion is the closest view. He (peace be upon him) sought the help of Mushriks in the Battle of Hunayn in return for a share of the booty. AlHadwiyyah stipulated that the Imam should have with him a group of Muslims who can execute the rulings. It is reported in Sharh Muslim that AlShafi`y said, "It is permissible to seek the help of the Mushrik who are trusted with the Muslims' affairs when necessary, otherwise it is Makruh."
According to Ijma` (consensus of scholars), it is permissible to seek the help of the hypocrites for the Prophet (peace be upon him) sought the help of `Abdullah ibn Ubay and his people.
The above mentioned are the opinions of the scholars that we could collect on this question. May Allah grant us success! Peace be upon our Prophet Muhammad, his family and Companions! `Abdul`Aziz ibn `Abdullah ibn Baz