Shaykh ‘Uthaymeen [رحمه الله]: “If you see your brother debating and disputing when the truth is clear and he does not want to follow it, you should flee from him in the same way as you flee from a lion. Tell him that you have nothing more than that to say to him, and let him be.”
[Sharh Hilyah Talib-ul-‘Ilm, Page 28]