Sunan an Nasai
3572
Sahih+2

It was narrated that Jarir said:"I saw the Messenger of Allah twisting the forelock of a horse with his two fingers, and saying: 'Goodness is tied to the forelocks of horses until the Day of Resurrection: Reward and spoils of war

SahihAbu Ghuddah
SahihAl-Albani