An attentive heart should be present during all forms of worship, especially in du’a and salah. We are requesting an audience with Allah (s.w.t.). The whole point of ‘ud’iyyah, supplications is that one calls out with a sincere heart to his Creator. This sincerity cannot be achieved if one calls out heedlessly, without earnestness. The Prophet Muhammad (s.a.w.) said, “Make du’a to Allah in a state that you are certain that your du’a will be responded to, and know that Allah does not respond to a du’a that originates from a heedless heart.” [This was recorded by Imam at-Tirmidhi (r.a.) and Imam al-Hakim (r.a.) from Abu Hurayrah (r.a.)]
Du’a must be made with an attentive heart, such that one knows exactly what one is asking for, and remembers Who he is asking from. It does not befit a servant to ask his Lord in a neglectful manner, such that he is not even aware of what he is saying, or using memorised sentences that he repeats over and over again without understanding these phrases and appreciating their meanings. This does not preclude Allah (s.w.t) from His Response but it is bad adab, manner.
Prophet Muhammad (s.a.w.) said, “Hearts are like vessels. Some have greater capacity than others. Therefore, O people, when you ask from Allah, all Glory and Praise be to Him, ask from Him in a state in which you are certain that your prayers will be answered, for verily Allah does not Accept from His slave any du’a that is made from a neglectful heart. [This was recorded by Imam Ahmad ibn Hanbal (r.a.) in his Musnad from Abdullah ibn Umar (r.a.)]
Imam an-Nawawi (r.a.) wrote in his al-Adhzkar, “Know that the purpose of du’a is that one have an attentive heart, as we have already mentioned, and the proofs for this are more than can be mentioned, and the knowledge of it is so apparent that it need not be discussed.”