The Messenger of Allah ﷺ said, "Goodness is tied to the forelocks of horses until the Day of Resurrection."
حدثنا إسحاق سمعت مالكا يحدث عن نافع
قال رسول الله ﷺ الخيل معقود في نواصيها الخير إلى يوم القيامة
Its isnad is sahih, and it is in the Muwatta 2:22. It has already appeared through other routes from Nafi, the last of them being 5783.