《论衡·卷九·问孔篇》
假使孔子只是想表扬赞美一下颜渊，称赞颜渊贤能，没有学生赶得上他，那名目多得很，何必去问子贡呢？
使孔子徒欲表善颜渊，称颜渊贤，门人莫及，於名多矣，何须问於子贡？
If Confucius just wanted to praise Yan Yuan, to praise his virtue and ability, and no students could match him, then there were many ways to do so. Why did he have to ask Zigong?