Ninth Reply:
They state that pleasure is the perception of what is congenial, while pain is the perception of what is uncongenial. Whether pleasure is itself identical with perception, awareness, and knowledge, or whether it arises because of them, in either case pleasure is confined to the perception of what is congenial. Consequently, perception and knowledge as such are neither pleasure in themselves nor do they necessarily produce pleasure; pleasure exists only when what is perceived is harmonious. The object that is known, felt, and grasped must therefore be inherently suited to the knower, the conscious perceiver, so that perceiving it becomes a delight.

It is well established that whatever accords with a thing is loved by it, and whatever conflicts with it is detested. Thus pleasure and pain require three elements: (1) a harmony or disharmony between the perceiver and the perceived, (2) love or aversion on the part of the perceiver toward the perceived, and (3) knowledge and perception of the object. Only after these elements are in place does pleasure or pain ensue. From this it becomes clear that the most perfect of all pleasures is the delight of beholding Allah, as the statements of the Prophets affirm.

Muslim relates in his Ṣaḥīḥ, on the authority of Ṣuhayb (may Allah be pleased with him), that the Messenger of Allah (peace and blessings be upon him) said:

"When the people of Paradise enter Paradise, a caller will announce, ‘O people of Paradise! You have a promise with Allah which He wishes to fulfill for you.’ They will respond, ‘What is it? Has He not brightened our faces, admitted us into Paradise, and saved us from the Fire?’ Then the veil will be lifted and they will gaze upon Him; nothing He will give them will be dearer to them than that vision. That is the Increase (al-ziyādah)."

This indicates that the pleasure of that vision surpasses every pleasure they had experienced before it.