Ibn Al Qayyim says:
“In short, there is nothing more beneficial for the heart than reading the Qur’aan and with contemplation and reflection…
If people were to possess a realization of what recitation of the Qur’aan with contemplation contains, they would devote themselves to it at the expense of anything else.
When the person reads it with reflection and he comes across an aayah that he is in need of, for the cure of his heart, he repeats it, even if he does so a hundred times or the whole night. Hence, to recite a single aayah of the Qur’aan with contemplation and reflection is better than reciting the Qur’aan to completion without any contemplation or reflection.
It is also more beneficial for the heart and more conducive to attaining eemaan and tasting the sweetness of the Qur’aan.”
[Miftaah Daar as-Sa’aadah, p. 204, quoted in “Causes Behind the Increase and Decrease of Eemaan” by Shaykh ‘Abdur-Razzaaq al-’Abbaad]