Shaykh al-Fawzān: The "niyyah" means "al-qaṣd" (the intent), and it is an action of the heart that people do not know. It is an action of the heart, and only Allāh, Glorified and Exalted, knows the intentions. Only Allāh knows the intents.
When a person gets up to perform wudū', then he already has the niyyah (intention). If he didn't have the niyyah, he wouldn't have gotten up to perform wudū'! When he comes to the prayer then he has intended to pray. Some say, "No, I didn’t have the intention!" and they insist that you have to say or do certain things. The fact that you came to the prayer and are standing before Allāh, then this is the intention for prayer—you have already intended to pray. And yet some say, "No, I didn’t intend," and then they start having waswās (whispers & doubts), they abort their action and they start over. We ask Allāh for safety.
Student (reading to Shaykh al-Fawzān): "And despite this, they accept the words of Satan that they did not intend to pray or did not desire it, stubbornly denying the clear evidence of their own certainty."
Shaykh al-Fawzān: Yes, then this person actually believes Satan, who tells him that he didn't have the niyyah for prayer. After starting the prayer, Satan whispers to him, "You didn’t intend, you didn’t intend to pray" or "You didn’t say the opening Takbīr," even though he had said it! "You didn’t do this..." And so Satan keeps confusing him. We ask Allāh for safety.
Source: https://www.youtube.com/watch?v=o3wcSbrhVSs
Question: "I experience whispers (waswās) regarding my intention during obligatory prayers. When I want to pray the ‘Asr prayer, I get whispers telling me that it's not ‘Asr, but Dhuhr or a Sunnah prayer, even though my intention is for the obligatory ‘Asr prayer. Is my prayer valid? Does the intention change due to these whispers? What should I do?"
Shaykh al-Fawzān: Firstly, the "niyyah" is the intent and resolve with the heart, and it is not permissible to verbalize it, because verbalizing it is an innovation (bid'ah) since neither the Prophet (ﷺ), nor his companions, nor any of the early generations did so. Verbalizing the intention is an innovation; it is sufficient for the intention to be in the heart, as its place is in the heart.
The whispers that a person experiences—whether he had the niyyah or not, or what the niyyah was—should be rejected! One should not pay attention to them! If a person gets up to pray or comes to the prayer, they have already made the intention. If they come to the prayer or stand for the prayer, the intention has already been made. There is no need for these whispers, nor should one pay attention to it. Rather, the person should intend the prayer, say the Takbīr, and complete their prayer without paying attention to Satan's whispering, such as "Did you intend? Did you not intend? Has your intention been broken?" or similar thoughts that confuse a person in their worship and through which Satan tries to overpower them.
Source: https://www.youtube.com/watch?v=w4AjhcmzcYc
Question: I heard that one of the conditions for a valid ablution (wudū') is to maintain the intention throughout, and this has increased the wasāwis (whispers) for me. When I reach the point of wiping the head (in wudū'), I start over, or when I get to the left arm, I also start again. Sometimes this happens more than four times. What do you advise me?
Shaykh al-‘Uthaymīn: We advise you by explaining that maintaining the intention simply means: not intending to interrupt or invalidate the wudū'. This is the meaning of maintaining the intention: that you do not intend to break it. It does not mean that you must be consciously remembering the intention from the start of the wudū' until the end. If the thought of your intention leaves your mind and you forget or become distracted, it does not harm your wudū' because maintaining the intention means not intending to break it.
If you reach the point of washing your head or your left arm and start doubting whether you have continued in your intention or not, then the aṣl (origin) is that the intention remains, so do not repeat your wudū'.
And I warn you against continuing in [entertaining] these whispers, because if you continue with it, it will not only affect your wudū', but it will also extend to your prayer and other acts of worship. At that point, you will always remain in a state of confusion and anxiety. The Prophet (ﷺ) put an end to this when he was asked about a man who imagined that he felt something during the prayer. The Prophet (ﷺ) said: "He should not leave the prayer until he hears a sound or smells an odor."
So, my brother, cut off these whispers from yourself! And know that if you were asked to perform actions without intention, you wouldn't be able to do so. Every rational person who understands what they are doing or saying, cannot say or do anything without intention. Yes.
Source: https://alathar.net/home/esound/index.php?op=codevi&coid=54920
Shaykh al-Uthaymīn:
"The niyyah (intention), irādah (will), and qaṣd (purpose, intent): all share the same meaning. Meaning, having the qaṣd for something is the same as having the niyyah for it, and having the irādah for something is also the same as having the niyyah for it.
Intention (niyyah) cannot be separated from a voluntary action, meaning that every action a person performs voluntarily must involve intention. This is why the Prophet ﷺ said: “Actions are judged by intentions.” There is no action without intention. Some scholars even said, "If Allāh had commanded us to perform an action without intention, it would be like asking us to do the impossible." For example, if Allāh said to us, "Perform wudū' without intention," or "Pray without intention," or "Fast without intention," or "Perform Ḥajj without intention," this would be like requiring us to do something beyond our capacity. Who can perform a voluntary action without intending to do it? This is impossible!
Thus, we understand that what happens to some people who suffer from waswās and say, “I didn’t intend,” is nothing but an illusion with no basis in reality. How can it be true that you did not intend when you have already performed the action?"
Source: https://www.alathar.net/home/esound/index.php?op=codevi&coid=98969
Translation: Yasin ibn Jamal