In one narration the wording is: The Prophet (peace and blessings be upon him) said this while placing both his hands on his two sides.
Al-Tabarani recorded it in al-Mu'jam al-Awsat, and al-Bazzar recorded it with the wording: "Whoever frightens the Ansar." The narrators of al-Bazzar are the narrators of the Sahih except Talib bin Habib, who is thiqah (trustworthy). Ahmad recorded something similar, except that his wording is: "Whoever frightens the people of Madinah." The narrators of Ahmad are the narrators of the Sahih.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب المناقب / 16511