Yes, the place of intention is the heart without doubt,
“Indeed all actions depend upon intention.” (Bukhaary 1)
It has not been recorded from the Prophet ﷺ that he ever uttered intention in words, and nothing is mentioned from him or any of his companions, recorded either in a weak a hadeeth or an authentic one. What is meant by this is that he ﷺ never expressed intention in words. It is for this reason that scholars have said that expressing intention in words is an innovation. This is because the place of making intention is the heart. Allaah says in the Qur’aan,
(قُلۡ أَتُعَلِّمُونَ ٱللَّهَ بِدِينِكُمۡ)
“Say, "Would you acquaint Allaah with your religion.”” (Al-Hujuraat 16)
Those who express intention in words such as saying, ‘I intend to pray such and such or I intend to do such and such behind the imam and the like….’ then this is of no value. Rather, the people of knowledge have considered this to be a matter of innovation in religion. And every new matter is an innovation in religion. Therefore, if a person intends to make ablution and stands from his place to go to the place of ablution and starts to wash his hands with water and then rinse his mouth and nose, wash his face intending with all of this that it is ablution then that is the intention which would complete his ablution. When a person stands for prayer and says Allaahu Akbar intending with it to start prayer which Allaah has made compulsory upon him then this is intention, nothing more, nothing less. Some people have the habit of, whenever they enter the toilet, or the wash area, and their ablution is broken, they out of instinct make ablution without realizing it. This is not sufficient. This is because his action is free of intention. However, if he were to intend to make ablution and stand from his place and he did not move from his place except for the intention of making ablution or wanting to pray then this is his intention. It does not require anything more than that. There is no doubt that intention is the foundation of deeds. No act of worship done for the sake of Allaah is valid except with intention. It is recorded in an authentic hadeeth and the Prophet ﷺ said,
“Indeed all actions depend upon intention.” (Bukhaary 1)
Therefore, intention is what validates deeds and distinguishes it between worship and habit.
(وَمَآ أُمِرُوٓاْ إِلَّا لِيَعۡبُدُواْ ٱللَّهَ مُخۡلِصِينَ لَهُ ٱلدِّينَ)
“… and they were not commanded except to worship Allaah,
being sincere to Him in religion.” (Al-Bayyinah 5)
Hence, any deed which is absent of sincerity has no value, nor is it valid. The condition for acts of worship to be accepted is that it must be sincerely done for the sake of Allaah and in accordance to the Sunnah of his Prophet ﷺ. Therefore, nothing can be accepted as an act of worship except those things instituted by the Prophet ﷺ. Believing this is a part of the declaration of faith in Muhammad ﷺ as the Messenger of Allaah. Al-Fudhayl ibn ‘Iyaadh said regarding the statement of Allaah,
(لِيَبۡلُوَكُمۡ أَيُّكُمۡ أَحۡسَنُ عَمَلٗاۚ)
“He who created death and life to test you as to which of you is best in deed.” (Al-Mulk 2)
Best indeed in terms of the sincerest and the most correct. It was said to him, ‘Abu ‘Aly! What is sincerest and most correct?’ He said ‘If the deed is done sincerely for the sake of Allaah but not done in the correct manner, meaning according to the Sunnah of the Messenger of Allaah ﷺ then it is not accepted. And if it is according to the Sunnah of the Prophet ﷺ but not done sincerely for the Sake of Allaah, it is not accepted.’