耳 聽 為 虛 眼 見 為 實

耳聽為虛，眼見為實

耳听为虚，眼见为实

er3 ting1 wei2 xu1 , yan3 jian4 wei2 shi2

Take what you hear to be false, only believe it when you see it (俗语 common saying). Don't believe what people tell you until you see if for yourself. It ain't necessarily so.