Believers in their mutual care for each other are like one body
the Messenger of Allah ﷺ said, "The similitude of believers in their mutual love, mercy, and affection is that of one body: when any limb of it aches, the whole body aches because of sleeplessness and fever."
قَالَ رَسُولُ اللَّهِ ﷺ: «مَثَلُ الْمُؤْمِنِينَ فِي تَوَادِّهِمْ وَتَرَاحُمِهِمْ وَتَعَاطُفِهِمْ مَثَلُ الْجَسَدِ إِذَا اشْتَكَى مِنْهُ عُضْوٌ تَدَاعَى لَهُ سَائِرُ الْجَسَدِ بِالسَّهَرِ وَالْحُمَّى۔»