《北史·列传·卷六十二》
周武帝在太后丧葬期间，与身边的人出外打猎，张衡散开发髻，载着棺材跟随周武帝，扣住马首直言劝谏。
周武帝居太后忧，与左右出猎，衡露髻舆榇，扣马切谏。
During the funeral of the empress dowager, Emperor Wu of Zhou went out hunting with his entourage. Zhang Heng disheveled his hair, carried the coffin, followed Emperor Wu, and held the horse's head to remonstrate with him directly.