From Sahih Muslim (Hadith 971):
Jabir b. Samura reported:We said our prayer with the Messenger of Allah (ﷺ) and, while pronouncing salutations, we made gestures with our hands (indicating)" Peace be upon you, peace be upon you." The Messenger of Allah (ﷺ) looked towards us and said: Why is it that you make gestures with your hands like the tails of headstrong horses? When any one of you pro- nounces salutation (in prayer) he should only turn his face towards his companion and should not make a gesture with his hand
Reference: Muslim 971