If the Hadith narrated by Malik indicates that the Prophet (peace be upon him) was free to choose between seeking the help of the Mushriks or refusing their help, and that he would even refuse to seek the help of a Muslim if he doubts it, then the two Hadith will not be in conflict with each other. If, however, it [the Hadith narrated by Malik] indicates that the Prophet (peace be upon him) refused the man's desire to participate with them in battle because the latter was a Mushrik, the answer will be that this Hadith was abrogated by the other Hadith which showed that he sought their help afterwards.
It is permissible to seek the help of Mushriks to fight against other Mushriks, if they are willing to help. It is not permissible to give them a share of the booty as it was not authentically reported that the Prophet (peace be upon him) did so.
Al-Shafi`y said, "He (peace be upon him) might have refused to let the Mushrik participate in the Battle of Badr, hoping that he would embrace Islam." He also added that it is permissible for the Muslim leader to turn down a Mushrik or to give him permission. The opinion of Al-Shafi`y wa transmitted by Al-Bayhaqy. [End of quotation].
Al-Nawawy (may Allah be merciful with him) stated in his book, "Sharh Sahih Muslim", (vol.12, pp.198-199), "The Hadith narrated on the authority of `Aishah (may Allah be pleased with her) that the Prophet (peace be upon him) set out to Badr, and when he reached Harrat Al-Wabarah which is four miles from Madinah and the Prophet (peace be upon him) said, "Go back for I will not seek the help of a Mushrik." According to another Hadith, the Prophet (peace be upon him) sought the help of Safwan ibn Umayyah before the latter embraced Islam; so a group of scholars based their argument on the first Hadith in general.
Al-Shafi`y and other scholars said that it is permissible to seek the help of disbelievers, if they offer good advice to Muslims and when it is necessary; otherwise it is Makruh (reprehensible). The two Hadith are interpreted with this meaning. However, if a disbeliver is given permission to participate, he should not receive a share of the booty. Allah knows best! [End of quotation].
Ibn Hubayrah, the Vizier, stated in his book, "Al-Ifsah `an Ma`any Al-Sihah" (vol. 2, p. 286): Scholars held different views regarding seeking the help of the Mushriks to fight against the enemies. Malik and Ahmad maintained that it is not permissible to seek the help of the Mushriks at all. However, Malik added that it is permissible to seek their help if they are in the service of the Muslims. Abu Hanifah believed that it is permissible to seek their help absolutely if they are under Islamic rule; otherwise it is Makruh to use them.
Al-Shafi`y said that it is permissible to seek the help of Mushriks but on two conditions: First, the Muslims are few in number while the Mushriks are great in numbers. Second, the Mushriks hold good opinions about Islam and are inclined to it. There is no harm in taking their advice but they should not receive a share of the booty. However, Ahmad in one of his two narrations said that it is permissible to give them a share of the booty. Al-Shafi`y said: If they were hired, they should be paid from the money which has no owner. He also said that they should be given from the spoils. Al-Wazir said: I believe that this case should be treated exactly the same as the cases of Jizyah (poll tax required from non-Muslims living in an Islamic state) and Kharaj (tax on agricultural land). [End of quotation].
Second, a group of scholars said that it is permissible to seek the help of Mushriks in fighting against other Mushriks when necessary. They based their argument on a lot of evidence among which is Allah's saying in Surah Al-An`am, while He has explained to you in detail what is forbidden to you, except under compulsion of necessity
Al-Hazimy (may Allah be merciful with him) reported that a group of scholars permitted seeking the help of Mushriks on two conditions: A. The Muslims are few in number, so seeking the help of the Mushriks becomes necessary. B. It is permissible to allow the Mushriks who are trusted with Muslims' affairs.
Those who are of the opinion that seeking the help of the Mushriks is permissible cited as evidence the Hadith which was reported byAhmad and Abu Dawudon the authority of Dhu Makhmar who said that he heard the Messenger of Allah (peace be upon him) say, You will make a peace-treaty with the Romans and together you will invade an enemy beyond Rome. You will be victorious and take much booty...
Al-Majd Ibn Taymiyyah said in his book, "Al-Muharar fi Al-Fiqh" (vol. 2, p. 171): "It is not permissible to seek the help of the Mushriks unless it is necessary. If the Muslim army will increase in strength by joining the Mushrik army and they will both form a powerful front against the enemy, and they [the Mushriks] hold good opinions about Islam, it will be permissible; otherwise it is not. [End of quotation].
Al-Muwaffaq stated in Al-Muqni` (vol. 1, p. 492): "It is not permissible to seek the help of the Mushriks except when necessary."