《资治通鉴·晋纪·晋纪二十四》
郗的儿子郗超是桓温的参军，拿来信看过后，便把信撕碎，重新改写了一封，信中诉说自己不是将帅之才，不能胜任军旅重任，而且年老多病，请求找一个悠闲的地方休养，劝说桓温把郗自己的部队一并统领。
愔子超为温参军，取视，寸寸毁裂，乃更作愔笺，自陈非将帅才，不堪军旅，老病，乞闲地自养，劝温并领己所统。
Xi's son, Xi Chao, was Huan Wen's military advisor. After reading the letter, he tore it up and rewrote it. In the new letter, he said that he was not talented enough to be a general or fulfill the heavy responsibilities of military service, that he was old and in poor health, and asked to have a quiet place to recuperate. He advised Huan Wen to take over his troops as well.