The Command To Be Calm During The Prayer And The Prohibition Of Gesturing With One's Hand And Raising It When Saying The Salam; And Completing The First Rows, Aligning In Them, And The Command To Come Together Sahih Muslim 431 a
Translation
Jabir b. Samura reported
When we said prayer with the Messenger of Allah (ﷺ), we pronounced: Peace be upon you and Mercy of Allah, peace be upon you and Mercy of Allah, and made gesture with the hand on both the sides. Upon this the Messenger of Allah (may peace be upon him said: What do you point out with your hands as if they are the tails of headstrong horses? This is enough for you that one should place one's hand on one's thigh and then pronounce salutation upon one's brother on the right side and then on the left.