A Muslim is a Mirror for His Brother

إِنَّ أَحَدَكُمْ مِرْآةُ أَخِيهِ فَإِنْ رَأَى بِهِ أَذًى فَلْيُمِطْهُ عَنْهُ (الترمذي)

"Each of you is a mirror for his brother. If he sees something bad, let him remove it for him."

• A mirror allows us to see and correct defects which we would not otherwise see.
• If you can imagine a society in which there are no mirrors nor anything equivalent to mirrors, that is how to imagine a society where there is no ordering right and forbidding wrong, no gatherings, socializing, mixing and mingling as well as cooperating in all that is goodness and piety.  That is ugly community and and ugly society.
• When a believer helps his brother to see what needs correcting, he is like a fine, well-lit mirror.
• The meaning is: BE for your brother Muslim like a mirror. You wish to improve his condition and aid him in all that is good and keep him clear from arrogance and pride.
• Show your brother whatever is not beautiful about him and which needs correction SUBTLELY and with compassion and respect.
• Advise him but don't scandalize or embarrass him.
• You are his mirror for him to see his true state through you and he is your mirror to help you see your true state through him.
• If you see good in your brother, that is for YOU as you will seek to imitate and follow him in that good.
• And, if you see other than that in him, that, too, is for YOU as you will know to avoid falling into what you have seen.
• As you can see, for the believer, all forms of mixing with the Muslims is nothing but good.
• In hadith: "The allies of Allah are those who remind you of Allah when you see them."

عَنْ أَبِي هُرَيْرَةَ عَنْ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ الْمُؤْمِنُ مِرْآةُ الْمُؤْمِنِ وَالْمُؤْمِنُ أَخُو الْمُؤْمِنِ يَكُفُّ عَلَيْهِ ضَيْعَتَهُ وَيَحُوطُهُ مِنْ وَرَائِهِ (أبو داود)

"The believer is a mirror for the believer. The believer is the brother of the believer. He guards his resources and surrounds him with his care and protection."

• Allah said, {The believers are nothing but brothers} (Al-Hujuraat:10).
• A believer is watchful and protective of another's land, house, etc. just as his own.
• Like this hadith as well:

النُّعْمَانِ بْنِ بَشِيرٍ قَالَ قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ مَثَلُ الْمُؤْمِنِينَ فِي تَوَادِّهِمْ وَتَرَاحُمِهِمْ وَتَعَاطُفِهِمْ مَثَلُ الْجَسَدِ إِذَا اشْتَكَى مِنْهُ عُضْوٌ تَدَاعَى لَهُ سَائِرُ الْجَسَدِ بِالسَّهَرِ وَالْحُمَّى

"The similitude of the believers in their mutual affection, mutual compassion and mutual empathy is like a single body. When any member of that body hurts, all of its parts are involved and affected with sleeplessness and fever."

مَنْ أَكَلَ بِرَجُلٍ مُسْلِمٍ أَكْلَةً فَإِنَّ اللَّهَ يُطْعِمُهُ مِثْلَهَا مِنْ جَهَنَّمَ وَمَنْ كُسِيَ ثَوْبًا بِرَجُلٍ مُسْلِمٍ فَإِنَّ اللَّهَ يَكْسُوهُ مِثْلَهُ مِنْ جَهَنَّمَ وَمَنْ قَامَ بِرَجُلٍ مَقَامَ سُمْعَةٍ وَرِيَاءٍ فَإِنَّ اللَّهَ يَقُومُ بِهِ مَقَامَ سُمْعَةٍ وَرِيَاءٍ يَوْمَ الْقِيَامَةِ (أبو داود)

"Whoever eats a morsel of food on the back of another Muslim will be fed that much by Allah in hell-fire. Whoever benefits a garment at the expense of another Muslim will be dressed like that by Allah in hell-fire. Whoever stands before a Muslim in a position of boasting and showing off, Allah will stand in just such a position in relation to him on Qiyama."

• Meaning: A man goes to the enemy of his "friend" and talks in a bad way about his "friend" in order to gain favors from the other.

• Allah will remove all blessing from such worldly gains.

• In this hadith is knowledge about some of the food and dress of the people of hell-fire.

• "Stand in a position of boasting"

• a) Boasts about the goodness of another for his own personal purposes and gain.

• b) Convinces people of the good qualities of powerful people for his own gain when that person does not possess them.