Leaving that which does not concern a Muslim

On the authority of Abu Hurairah (radiAllaahu 'anhu) who said: The Messenger of Allaah (sallAllaahu alayhi wa sallam) said:

Part of the perfection of one's Islaam is his leaving that which does not concern him.
A Hasan (Good) Hadeeth which was related by at-Tirmidhee and others in this fashion.

Explanation of Hadeeth 12
And this hadeeth has also been narrated by Qurrah bin 'Abd-ir-Rahmaan from [the great Muhaddith] az-Zuhree, from Abee Salamah from Abee Hurairah, and he considered its chains of narration Saheeh (Authentic), and then he said regarding the hadeeth that it is from the Comprehensive speech that contains many significant meanings, and all this in very few words. And similar to this [hadeeth] is the statement of Abu Dharr (radiAllaahu anhu) in some of his narrations from the Prophet (sallAllaahu alayhi wa sallam) that he said:
"And whoever accounts his speech by his actions, then his speech will be very little except in that which concerns him".
And Imaam Maalik mentioned that it reached him that it was said to Luqmaan: "What has enabled you to attain what we see in you of Grace and Blessing ?" to which he replied:

"Speaking the Truth, returning the Trusts, and leaving that which does not concern me."
And it has been narrated from Hasan [al-Basree] that he said:

"From the signs that Allaah ta'aalaa has turned away from the slave is that he finds himself continually engaged in those matters which are not of his concern."
And Abu Daawood as-Sijistaanee said:

"The basic principles of the Sunnah in each branch of learning are based upon four ahaadeeth"
and he mentioned among them this hadeeth.


Summary
That prying and interfering in others affairs is a sign of not being a good Muslim