Hexagram H51 is named 震 (zhèn), Shake,the arousing (shock, thunder); thunder, excite, thrill, convulse, and tremor. The advice is to maintain one’s concentration (one did not lose the sacrificial wine in the ladle). Its inner (lower) trigram is ☳ (震 zhèn) shake = (雷) thunder, and its outer (upper) trigram is identical.