《魏书·帝纪·卷二》
八月乙巳，到达柴壁，姚平固守，进军包围他，姚兴出动全部军队来救援。
八月乙巳，至于柴壁。平固守，进军围之。姚兴悉举其众来救。
On the yisi day of the eighth month, he reached Chaibi; Yao Ping held out stubbornly, the advance army surrounded him, and Yao Xing marched all his troops to his rescue.