عَنْ أَنَسِ بْنِ مَالِكٍ رَضِيَ اللَّهُ عَنْهُ عَنْ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ قَالَ مَا مِنْ مُسْلِمَيْنِ الْتَقَيَا فَأَخَذَ أَحَدُهُمَا بِيَدِ صَاحِبِهِ إِلَّا كَانَ حَقًّا عَلَى اللَّهِ أَنْ يَحْضُرَ دُعَاءَهُمَا وَلَا يُفَرِّقَ بَيْنَ أَيْدِيهِمَا حَتَّى يَغْفِرَ لَهُمَا
Sayyiduna Anas bin Malik (may Allah be pleased with him) narrates that the Noble Prophet (peace and blessings be upon him) said: When two Muslims meet each other and one of them takes the other's hand and shakes hands, it is incumbent upon Allah to participate in their supplication (i.e., to accept it), and He does not separate their hands until He has forgiven them.