Hexagram 51 is named 震 (zhèn), "Shake". Other variations include "the arousing (shock, thunder)" and "thunder". Both its inner and outer trigrams are ☳ (震 zhèn) shake = (雷) thunder
ZT:易經》第四十卦雷水解
The Image 雷水解 Thunder and rain set in.
震上坎下 Zhèn (The Arousing, Thunder) above, Kǎn (The Abysmal, Water) below,
The Judgment 解‧利西南‧無所往‧其來復吉‧有攸往‧夙吉‧ In (the state indicated by) Xiè advantage will be found in the south-west. If no (further) operations be called for, there will be good fortune in coming back (to the old conditions). If some operations be called for, there will be good fortune in the early conducting of them.
彖曰‧解‧險以動‧動而免乎險‧解‧
解利西南‧往得眾也‧其來復吉‧乃得中也‧有攸往夙吉‧往有功也‧
天地解而雷雨作‧雷雨作而百果草木皆甲坼‧解之時義大矣哉‧
In Xiè we have (the trigram expressive of) peril going on to that expressive of movement. By movement there is an escape from the peril:--(this is the meaning of) Kieh.
'In (the state indicated by) Xiè, advantage will be found in the south-west:'--the movement (thus) intimated will win all. That 'there will be good fortune in coming back (to the old conditions)' shows that such action is that of the due medium. That 'if some operations be necessary, there will be good fortune in the early conducting of them' shows that such operations will be successful.
When heaven and earth are freed (from the grasp of winter), we have thunder and rain. When these come, the buds of the plants and trees that produce the various fruits begin to burst. Great indeed are the phenomena in the time intimated by Xiè.
象曰‧雷雨作‧解‧君子以赦過宥罪‧ (The trigram representing) thunder and that for rain, with these phenomena in a state of manifestation, form Xiè. The superior man, in accordance with this, forgives errors, and deals gently with crimes.
Line 1 初六‧無咎‧ The first SIX, divided, shows that its subject will commit no error.
象曰‧剛柔之際‧義無咎也‧ The strong (fourth) line and the weak line here are in correlation:--we judge rightly in saying that 'its subject will commit no error.'
Line 2 九二‧田獲三狐‧得黃矢‧貞吉‧ The second NINE, undivided, shows its subject catch, in hunting, three foxes, and obtain the yellow (= golden) arrows. With firm correctness there will be good fortune.
象曰‧九二貞吉‧得中道也‧ 'The good fortune springing from the firm correctness of the second NINE, (undivided),' is due to its subject holding the due mean.
Line 3 六三‧負且乘‧致寇至‧貞吝‧ The third SIX, divided, shows a porter with his burden, (yet) riding in a carriage. He will (only) tempt robbers to attack him. However firm and correct he may (try to) be, there will be cause for regret.
象曰‧負且乘‧亦可醜也‧自我致戎‧又誰咎也‧ For 'a porter with his burden to be riding in a carriage' is a thing to be ashamed of. 'It is he himself that tempts the robbers to come:'--on whom besides can we lay the blame?
Line 4 九四‧解而拇‧朋至斯孚‧ (To the subject of) the fourth NINE, undivided, (it is said), 'Remove your toes. Friends will (then) come, between you and whom there will be mutual confidence.'
象曰‧解而拇‧未當位也‧ 'Remove your toes:'--the places (of this line and of the third and first) are all inappropriate to them.
Line 5 六五‧君子維有解‧吉‧有孚于小人‧ The fifth SIX, divided, shows (its subject), the superior man (= the ruler), executing his function of removing (whatever is injurious to the idea of The Judgment), in which case there will he good fortune, and confidence in him will be shown even by the small men.
象曰‧君子有解‧小人退也‧ When 'the superior man executes his function of removing (whatever is injurious to the idea of The Judgment),' small men will of themselves retire.
Line 6 上六‧公用射隼于高墉之上‧獲之無不利‧ In the sixth SIX, divided, we see a feudal prince (with his bow) shooting at a falcon on the top of a high wall, and hitting it. (The effect of his action) will be in every way advantageous.
象曰‧公用射隼‧以解悖也‧ 'A prince with his bow shoots a falcon:'--thus he removes (the promoters of) rebellion.
_______________________________
ZT雷水解
30三十、雷水解 震木二世卦
解象德:震春、坎冬，為冬去春來。又震動而下雨，雷雨交作，則天地之鬱熱之氣解散。又坎為險陷，震為動盪，從險境中撼動擺脫，而得免乎險為解也。
十二月卦： 春平 夏吉 秋凶 冬不利
評曰;涉川未乾之象，雷雨緩散之意。
判斷:得此卦時，即可解脫從前之險難，但僅為脫困，而喜末至。元氣末復之時，猶如人病之初癒，血氣末復之際，又因困難始怯，欲加害者猶在，務必去除之。諸事宜早日進行策劃，遲即難調或遭破壞。有與遠方通交之意，可得有力人士，宜速至疾哌M行，遲即有錯。
斷之婚姻可成，但有不測之妨礙。故稍有帶破。男人占得此卦得利，女人占得此卦不利，有春情之動。若是歸舍者吉利，名份末定者定有損節，宜慎之。
參考:雷上坎下，中爻約坎互離，坎為水，震為雷，雷雨交作則能解散熱氣，故日解。然解是化散而潤和，又言處理、化育、化氣。此卦有春雨初降，大地潤和，萬物欣欣向榮，動物受春情之動，雷雨交接承歡，滋養萬物之象也。於人事可化于戈為玉帛，均為解也。此卦楚霸王項羽受困咳下卜得之，後果士卒潰散也。因本身陷於坎困，而外卦
為震動，外動而內困，故其兵士潰解也。
解：表解決之象。主凶帶小吉之象。冬雪春化之意。冰凍三尺非一日之寒，事出有因、但已是到該解決的盡頭了！只是化解之日還很長，要抓住重點方向，好好努力堅持下去，還是有可能再成功的。
