Imam Abi Zayd al-Qayrawaanee (May Allah have mercy on him) says:
"The Hadiths of morals and manners have been combined into four narrations. They are:

1. The Prophet ﷺ said: "Whoever believes in Allah and the last day then let him say (a word that is) good or be silent."

2. The Prophet ﷺ said: "From the goodness of a person's Islam is that he leaves off that which does not concern him."

3. The Prophet ﷺ said to the one who sought advice from him: "Do not become angry!"

4. The Prophet ﷺ said: "None of you (truly) believes until he loves for his brother, what he loves for himself."

Hence, these four narrations- are all from forty hadeeth of the narrations collected by Imam Nawawee (May Allah be pleased with him).

All of the Hadiths related pertaining to conduct, return back to these four narrations.
This benefits us (knowing) that whoever is given success toward the understanding of these narrations, as well as the application of them then verily the pillars of conduct will be gathered with him and that which they stand upon.

Explaining The 4 Pillars of Noble Manners -

The first pillar: Safeguarding the tongue and its evidence is the statement of the prophet ﷺ : “Whoever believes in Allah and the last day, then let him say (a word that is) good or be silent.” This is the first pillar, and whoever does not safeguard his tongue will not be from the people of morals and manners.

Hence, from the tremendous foundations and strong supports which morals and manners are established upon…is safeguarding the tongue. Meaning: taking it into account and holding it back from speech, except for what is beneficial in it.

So, the prophet ﷺ said: “…then let him speak good or be silent.” In it is a call to pondering over one’s speech prior to speaking; because speech, before it exits, you own it…and when it has exited it owns you! For this reason, from the beauty of an individual is that he reflects upon his statement before he speaks.

The second pillar from the pillars of morals and manners:
Distancing oneself far away from meddling and being involved in what does not concern him; and that the individual does not delve himself into what does not concern him.

Thus, the meddling person will not be one of morals and good manners, because his meddling and delving himself into what does not concern him removes him from good manners and takes him outside of its boundary.

However, when he is far away from meddling…he is far away from entering into what does not concern him. Hence, this is from the characteristics of good manners. Rather it is from the pillars of good manners. The proof of this is the statement of the prophet ﷺ : “From the goodness of the person’s Islam is that he leaves off what does not concern him.”

The third pillar from the pillars of morals and good character: the avoidance of being driven by human emotions, in particularly anger.

When the person gets excited and he becomes angry, upon him is that he does not proceed at the time of his anger. Meaning that he does not carry out a statement or an action because any statement he carries out at the times of anger, and any action he carries out at the time of anger, in most cases will be away from the realm of morals and manners. Surely, it has been said regarding the dispraise of anger and its ugliness: “Anger…the first part of it is insanity and the final ........