From Sahih Bukhari (Hadith 7050):
Narrated Sahl bin Sa`d:I heard the Prophet (ﷺ) saying, "I am your predecessor at the Lake-Fount (Kauthar), and whoever will come to it, will drink from it, and whoever will drink from it, will never become thirsty after that. There will come to me some people whom I know and they know me, and then a barrier will be set up between me and them
Reference: Bukhari 7050