The Messenger of Allah ﷺ said, "Whoever frightens the people of Medina, upon him is the curse of Allah, the angels, and all of mankind. Allah will accept from him no obligatory deed nor any voluntary one. Whoever frightens the people of Medina has frightened what is between these two," meaning his heart.
قال رسول الله ﷺ: من أخاف أهل المدينة فعليه لعنة الله والملائكة والناس أجمعين لا يقبل الله منه صرفا ولا عدلا، من أخاف أهل المدينة فقد أخاف ما بين هاتين يعني قلبه.
Ibn Abu Shayba narrated it in his Musannaf (33094), and Harith in his Musnad as found in Bughyat Bahith (394), both of them through Hashim bin Hashim bin Utba bin Abu Waqqas Zuhri, from Abdullah bin Nistas, from Jabir bin Abdullah, who said what has already been mentioned.Its chain of transmission is hasan, on account of Abdullah bin Nistas (with the nun vowelled with a kasra) al-Madani, the freedman of Kinda, from whom no one narrated except Hashim bin Hashim bin Utba bin Abu Waqqas. That is why Dhahabi said in al-Mizan, "He is not known, Hashim bin Hashim alone narrated from him." So he said.However, Ibn Hajar quoted in Tahdheeb from Abu Umar Sadafi, who said, Muhammad bin Qasim, that is Ibn Yasar, narrated to us, saying, I heard Nasai say, Abdullah bin Nistas is trustworthy. If this statement from Nasai is confirmed, then at the very least his hadith is hasan.