Explanation of the words of Imam al-Nawawi (may Allah have mercy on him) regarding what he quoted: "

The Shaykh : In the name of Allah, the Most Gracious, the Most Merciful.
The author (may Allah have mercy on him) stated, in what he quoted from Abu Hurayrah (may Allah be pleased with him) from the Prophet (peace and blessings be upon him), that he said: A person’s Islam is his submission to Allah (Mighty and Majestic), both outwardly and inwardly. As for inwardly, it is the servant’s submission to his Lord by rectifying his creed and his heart, such that he believes in everything in which belief is obligatory, as mentioned previously in the hadith of Jibril. As for outward submission, it is rectifying one’s outward actions, such as one’s words with the tongue and one’s deeds with the limbs. People differ greatly in their Islam, just as they differ in their forms and appearances: some are tall, some are short, some are large, some are less so, some are ugly, and some are beautiful; they differ in an obvious way. Likewise, they differ in their Islam to Allah (Mighty and Majestic), until Allah the Exalted said in His Book: Since people differ in their Islam, one of the things that increases the excellence of a person’s Islam is that he leaves what does not concern him, as the Prophet (peace and blessings be upon him) said in this hadith: This means what does not concern him, neither in his religion nor in his worldly affairs. So if a Muslim wants to make his Islam excellent, let him leave what does not concern him. Leave the thing that does not concern you. For example, if it is an action and you are hesitating whether to do it or not, look at whether it is among the important matters in your religion and your worldly affairs; if so, do it, and if not, leave it, for safety is safer. Likewise, do not interfere in the affairs of people if it does not concern you. This is contrary to what some people do today. You find some people eager to know the conditions of others. They approach two people who are talking, trying to get close to them to hear what they are saying. They find a person who has come from a certain direction and search, and perhaps they force the person to say to them, “Where did you come from? What did so-and-so say to you? What did you say to him?” and the like, in matters that do not concern them and do not matter to them. So leave the thing that does not concern you, for that is part of the excellence of your Islam. It is also a source of comfort; it is comfort for the person that he does not concern himself with anything but himself. That is the comfort. As for the one who follows the conditions of people, what was said, what they said, and what was said to them, he will be greatly tired and will miss out on much good, even though he does not benefit from it.
So make your habit the habit of yourself; let your concern be for yourself. Look at what benefits you and do it; leave what does not benefit you, for you have no stake in it, and this is not part of the excellence of your Islam. You are searching for things that do not concern you. If we were to follow this, and a person’s habit became the habit of himself, looking only at his own actions—what he did and what he produced—he would achieve much good. But you find some people occupied with the affairs of others in things that are of no benefit to them; they waste their time, occupy their hearts, scatter their thoughts, and lose many interests. You find the diligent man, whose only concern is himself and what concerns him, to be productive and fruitful, achieving things and being in mental and spiritual comfort. For this reason, this hadith is counted among the comprehensive words of the Prophet (peace and blessings be upon him). If you want to do something, whether in action or omission, look at whether it concerns you or not. If it does not concern you, leave it, do not expose yourself to it, and rest from it; let your heart, your thoughts, your mind, and your body rest. If it does concern you, in any case, be a sensible person, as came in the previous hadith: For every sensible person strives to work for what is after death and holds himself accountable for his deeds. And success is from Allah.