Shaykh al-Islaam ibn Taymiyyah was asked:
Question 1: Concerning the one who causes confusion in the lines of prayer and those around him by articulating the intention loudly. This was objected to but it did not deter him from persisting in this. A person said to him, what you are doing is not from the religion of Allaah and you are contradicting the Sunnah. He replied, this is from the religion of Allaah which He sent His Messengers with and it is obligatory upon every Muslim to do this and similarly the Qur`aan should be recited loudly behind an imaam. So did the Messenger of Allaah (sallallaahu `alaihi wasallam) or any one of his Companions use to do this? Did any one of the Four Imaams or any of the Muslim scholars enjoin this? And if the Messenger of Allaah (sallallaahu `alaihi wasallam) and his Companions and the scholars did not do this in prayer then what is obligatory upon the one who attributes this to them and does this? Is it permissible for a Muslim to come to his aid with even one word if he does this and attributes this to the religion by saying to those who are objecting, 'everything that he is doing in his religion is what he desires and your objection is based upon ignorance!' So are they correct in this or not?
All praises and thanks are due to Allaah. Articulating the intention in a loud voice is not legislated according to the opinion of all the Muslim scholars. The Messenger of Allaah (sallallaahu `alaihi wasallam) did not do it and neither did his Khaleefs, Companions, or the Salaf of this nation and their Imaams. Hence whosoever claims that this is part of the Religion of Allaah and that it is obligatory then it is necessary to teach him the Sharee`ah and ask him to repent from this opinion and if he still persists in this saying then he is to be killed. Rather the intention that is obligatory for the actions of worship such as wudu, ghusl, salaah, siyaam and zakaah etc. finds its place in the heart by agreement (ittifaaq) of the Imaams of the Muslims.
The intention is the desire to do something and the place for desire is in the heart and not upon the tongue by agreement of those possessing intelligence. So if a person were to intend something in his heart then this intention would be correct and proper according to the Four Imaams and in fact all of the Imaams of the Muslims - their former ones and latter ones there is no difference concerning this arising from those that deserve to be followed and those whose rulings deserve to be paid consideration.
However some of the later followers of the Imaams thought that the articulation of the intention was obligatory but they did not say that doing so in a loud voice was obligatory. Despite this, their opinion is erroneous, contradicting the consensus (ijmaa) of the Muslims. This due to the fact that it is known by necessity in the Religion of Islaam to the one who knows the Sunnah of the Messenger of Allaah (sallallaahu `alaihi wasallam) and the sunnah of his Khaleefs and knows how the Companions and their students used to pray that they did not articulate the intention and neither did the Prophet (sallallaahu `alaihi wasallam) command them to do so and neither did he teach this to any of his Companions.
Instead it is established in the Saheehs of Bukhaaree and Muslim that he (sallallaahu `alaihi wasallam) said to the Bedouin, "when you stand for prayer say the takbeer and then recite what is easy for you from the Qur`aan."
In the Sunan it is reported from him (sallallaahu `alaihi wasallam) that he said, "the key to prayer is purification, it is entered by saying the takbeer and exited by saying the tasleem."
In Saheeh Muslim from Aa`ishah (RA) that the Prophet (sallallaahu `alaihi wasallam) used to start the prayer by saying the takbeer and reciting 'All praise is due to Allaah
.' [i.e. al-Faatihah].
It is established by mutawaatir transmission and the consensus of the Muslims that the Prophet (sallallaahu `alaihi wasallam) and the Companions used to commence the prayer with the takbeer and it is not reported by a Muslim, neither from the Prophet (sallallaahu `alaihi wasallam) or from his Companions, that they used to articulate the intention be it silently or loudly. It is known that had the case been otherwise then for sure it would have been reported for it is known that it is impossible according to the Sharee`ah and habit for the people reporting something mutawaatir to hide such a thing. Therefore due to the fact that no-one reports this it is safe to say with certainty that it did not occur.