Book of Jin 648, vol. 74: biography of Huan Chong: "沖深以根本為慮,乃遣精銳三千來赴京都。謝安謂三千人不足以為損益,而欲外示閒暇,聞軍在近,固不聽。報云:「朝廷處分已定,兵革無闕,西籓宜以為防。」時安已遣兄子玄及桓伊等諸軍,沖謂不足以為廢興,召佐吏,對之歎曰:「謝安乃有廟堂之量,不閑將略。今大敵垂至,方游談不暇,雖遣諸不經事少年,眾又寡弱,天下事可知,吾其左衽矣!」" Fang Xuanling; et al., eds. (1974) [648]. Book of Jin 晉書 (in Chinese). Beijing: Zhonghua Shuju.