O you who have believed, if a wicked person brings you some news, inquire into it carefully lest you should harm others unwittingly and then regret what you have done.
(Al-Qur’an – 49:6)
When the tribe of the Bani al-Mustaliq embraced Islam, the Holy Messenger (peace and blessings of Allah be with him) sent Walid bin Uqbah to collect the zakat from them. When he arrived in their territory, he became scared due to some reason and without visiting the people of the tribe returned to Madinah and complained to the Holy Messenger that they had refused to pay the zakat and had even wanted to kill him. On hearing this, the Holy Messenger became very angry and he made up his mind to dispatch a contingent to punish those people. According to some traditions he had despatched the contingent, and according to others, he was about to despatch it. In any case all agree that in the meantime the chief of the Bani al-Mustaliq, Harith bin Dirar arrived at the head of a deputation, and submitted: "By God, we did not at all see Walid; therefore, there could be no question of refusing to pay the zakat and wanting to kill him. We are steadfast to the Faith and have no intention to withhold the zakat." Then, this verse was sent down.
On this critical occasion when on account of believing in a baseless report a grave blunder was about to be committed, Allah gave the Muslims this guiding principle to be followed on receipt of news: ‘Whenever you receive important news bearing upon a vital matter, you should not accept it immediately but should first examine the man who has brought it. If he is an evil man whose report may not be authentic, you should inquire into it carefully to ascertain the truth instead of accepting it.’ From this Divine Command an important legal principle is deduced, the sphere of application of which is very vast. According to it, it is not permissible for a Muslim government to take any action against a person or a group or a nation on the basis of the reports provided by the secret agents whose character might be doubtful.