Yao wanted to hand the realm to Xu You, but Xu You ran off to the river to wash his ears.
Tips
culture
The story first appears in the 庄子. A later telling adds his friend 巢父, who was about to water his calf in the stream, saw Xu You washing his ears and led the calf upstream so it would not drink the dirtied water.
usage
The idiom 洗耳恭听 grew out of this ear-washing, but it now means 'to listen respectfully', often with a touch of irony.