 he said the part that comes to the tongue is thinner than the optic nerve because the hardness of this and the softness of that are equal to the thickness of that and the thinness of this.
قوله والجزء الذي يأتي اللسان أدق من عصب العين لأن صلابة هذا ولين ذاك يعادل غلظ ذلك ودقة هذا.