This is what the Qur'an teaches us to do...

This is what the Qur'an teaches us to do; Allah says, "Adam disobeyed his Lord, so his life became evil to him...." (Holy Qur'an, 20:121). This is so because Allah had prohibited him from eating of the forbidden tree.

Since Adam did eat of it, we must not say: "Adam followed his own ijtihad as opposed to the available text." Each and every Muslim has to keep himself at his limit rather than transgress and voice his own view in an issue regarding which an order permitting or prohibiting it had already been issued by Allah or His Messenger (S), for that will be obvious apostasy. Allah said to the angels, "Prostrate to Adam." This is an order.

"So they prostrated" (Holy Qur'an, 20:116); this is a positive response, an act of submission, an expression of obedience. The exception was Eblis: He followed his own view, so he said, "I am better than him; why, then, should I prostrate to him?!" Here we encounter a rebellion, a mutiny, regardless of who is better than who: Adam or Eblis.

This is why the most Glorified One says, "It does not behoove any believing man or woman to make any choice in their matter once Allah and His Apostle have decided it, and whoever disobeys Allah and His Messenger (S) surely strays off a manifest straying" (Holy Qur'an, 33:36).

It is to this fact that Imam Ja’far al-Sadiq (as) referred when he said once to Abu Hanifah, "Do not apply qiyas (analogy), for if it is applied to the Shari’a, it will be obliterated, and the first person to apply qiyas was Eblis when he said, ‘I am better than him; You created me of fire while creating him of dust' (Holy Qur'an, 7:12 and 38:76)." His statement that "... If it is applied to the Shari’a, it will be obliterated" is the best expression of the invalidity of qiyas .

If people follow their own diverse views in the face of available texts, there will be no Shari’a at all. "Had the truth followed their own (low) desires, the heavens and the earth and all those therein would then have perished" (Holy Qur'an, 23:71). Having made this brief express the principle of ijtihad , let us see how Khalid ibn al-Walid disobeyed the order issued by the Messenger of Allah (S) on another occasion when he was sent by the Prophet to Banu Juthaymah to invite them to Islam.

The Prophet did not order Khalid to fight anyone.