and rigid, not softening to the truth in acknowledgment and submission, or they are not dry and rigid.

The “first” is the hardened heart: rigid and dry, like a stone that takes no impression. Faith is not inscribed within it, nor is knowledge imprinted upon it, for that requires a soft, receptive place. The “second” must be one of two kinds: either the truth is firmly established within it and does not depart, owing to its strength together with its tenderness, or its tenderness is accompanied by weakness and laxity. The latter is the diseased heart, while the former is both strong and tender.

The heart resembles the limbs of the body—the hand, for example. A hand may be rigid and dry, unable to bend or grasp, or grasping only with violence: this resembles the hardened heart. Or it may be weak and diseased, rendered incapable by its weakness and disease: this resembles the diseased heart. Or it may grasp with strength and suppleness: this resembles the knowledgeable, merciful heart. Through mercy, it is free of hardness; through knowledge, it is free of disease, for this disease arises from doubts and misconceptions. Hence, those unlike these are described as possessing knowledge, faith, and humble submission.

His words:

“And so that those who have been given knowledge may know that it is the truth from your Lord, believe in it, and their hearts humbly submit to it.”

provide evidence that knowledge leads to faith—not that the people of knowledge