It is narrated from Ibn Abi Hudhail (may Allah have mercy on him) that Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) went with one of his companions to visit a sick person. When they entered the house, that companion began to look here and there. Sayyiduna Abdullah (may Allah be pleased with him) said to him: By Allah! If both your eyes were gouged out, that would have been better for you.
Benefits and Issues: ➊ The point is that Allah, the Exalted, has created eyes for obedience and submission, and you are using them in disobedience. It would have been better if you did not have eyes; at least you would not have committed this sin. ➋ From this, it is understood that even after entering someone’s house with permission, it is still necessary to guard one’s gaze. Casting unnecessary glances around someone’s house is contrary to modesty. ➌ Guiding friends, companions, and students in religious matters and preventing them from wrong actions is a sign of good friendship.
Source: Fadlullah al-Ahad: Urdu Commentary on al-Adab al-Mufrad, Page: 1305