The Prophet ﷺ said, "The protection granted by the Muslims is one, even the lowest of them may extend it. Whoever violates the protection given by a Muslim, upon him is the curse of Allah, the angels, and all people. On the Day of Resurrection, no compensation or ransom will be accepted from him."
عن النبي ﷺ قال: ذمة المسلمين واحدة، يسعى بها أدناهم فمن أخفر مسلما فعليه لعنة الله والملائكة والناس أجمعين، لا يقبل منه يوم القيامة عدل ولا صرف.
Muslim reported it in the book of Hajj (1371), from Abu Bakr bin Nadr bin Abu Nadr, who said, Abu Nadr narrated to me, who said, Ubaydullah Ashjai narrated to me, from Sufyan, from Amash, from Abu Salih, from Abu Hurairah, who said, and he mentioned it.