Messenger of Allah ﷺ said, "You see the believers as regards their being merciful among themselves and showing love among themselves and being kind, resembling one body, so that, if any part of the body is not well then the whole body shares the sleeplessness (insomnia) and fever with it."
قَالَ رَسُولُ اللَّهِ ﷺ تَرَى الْمُؤْمِنِينَ فِي تَرَاحُمِهِمْ وَتَوَادِّهِمْ وَتَعَاطُفِهِمْ كَمَثَلِ الْجَسَدِ إِذَا اشْتَكَى عُضْوًا تَدَاعَى لَهُ سَائِرُ جَسَدِهِ بِالسَّهَرِ وَالْحُمَّى