«ذمة المسلمين واحدة فإن جارت عليهم جائرة فلا تخفروها فإن لكل غادر لواء يعرف به يوم القيامة»
The Prophet (peace and blessings be upon him) said:
"The protection (granted) by the Muslims is one. So if anyone among them grants protection over them, do not violate it, for every betrayer will have a banner by which he will be recognised on the Day of Resurrection."
Hadith Referenceصحیح الجامع الصغیر / حرف الذال / 3435