《资治通鉴·晋纪·晋纪二十六》
周在前秦,秘密地给桓冲写信，报告前秦的密谋计策。后又逃奔到汉中，被前秦人抓获后赦免了。
周飏在秦，密与桓冲书，言秦阴计；又逃奔汉中，秦人获而赦之。
Zhou secretly wrote to Huan Chong in Qin, reporting Qin's secret plans and strategies. He then fled to Hanzhong, was captured by Qin, and was pardoned.