Abu Amr (may Allah have mercy on him) said: I heard Sayyiduna Sahl bin Hunayf (may Allah be pleased with him) say that the Messenger of Allah (peace and blessings be upon him) pointed with his hand towards Madinah and said: "It is a place of sanctity and safety."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9965