Mishkat al-Masabih
Sa'd reported God’s messenger as saying, “No one will act deceitfully towards the inhabitants of Medina without being dissolved as salt is dissolved in water.” Bukhari and Muslim.
وَعَنْ سَعْدٍ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «لَا يَكِيدُ أَهْلَ الْمَدِينَةِ أَحَدٌ إِلَّا انْمَاعَ كَمَا يَنْمَاعُ الْملح فِي المَاء»
Reference