he said and what comes from the two testicles from the kidney and in it is the passage in which the semen matures after it turns red and because of the many layers of its veins and the veins of the kidney as you know are very watery therefore there is blood in it that is very moist so that blood is very ready and transforms into semen and that is if something mixes with it that transforms it into the nature of semen.
قوله وما يأتي من الأنثيين من الكلية وفيه المجرى الذي ينضج فيه المني بعد احمراره ولكثرة معاطف عروقه وعروق الكلى كما عرفته كثيرة المائية فلذلك يكون فيها دم كثير الرطوبة فيكون ذلك الدم كثير الاستعداد والاستحالة إلى المنوية وذلك إذا خالطه ما يحيله إلى طبيعة المني.