《左传·昭公·昭公三十二年》
以前的成季友，是桓公的小儿子，文姜所宠爱的儿子。刚刚怀孕就占卜，卜人报告说： 生下来就有好名声，他的名字叫友，成为公室的辅佐。 
昔成季友，桓之季也，文姜之爱子也，始震而卜，卜人谒之，曰： 生有嘉闻，其名曰友，为公室辅。 
The former Cheng Jiyou was Duke Huan's youngest son and was favored by Duke Huan's wife, Weng Jiang. When she just became pregnant, she asked someone to make a divination. The diviner reported: As soon as you give birth, he will have a good reputation. His name shall be You. He shall serve as an aide to the Duke.