It is narrated from Sayyiduna Ibn Mas'ud (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "I will wait for you at the Pond of Kawthar. At that time, there will be a dispute regarding some people and I will be overpowered. I will say: 'O Lord! My companions?' It will be said: 'You do not know what new things they invented after you.'"
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 4180