The Messenger of Allah ﷺ said, "The best of my nation is the generation among whom I was sent, then those who follow them." Allah knows best whether he mentioned a third or not. He said, "Then there will come after them a people who love stoutness and who give testimony before they are asked to testify."
قال رسول الله ﷺ: خير أمتي القرن الذين بعثت فيهم، ثم الذين يلونهم، والله أعلم أذكر الثالث أم لا، قال: ثم يخلف قوم يحبون السمانة، يشهدون قبل أن يستشهدوا.
Muslim narrated it in the chapters on the virtues of the companions (2534) through several routes from Abu Bishr, from Abdullah bin Shaqiq, from Abu Hurairah, who mentioned it. In one of his wordings, "Abu Hurairah said, 'I do not know if it was twice or three times.'"