乾卦用九
乾为天 · 周易第 1 卦
用九：见群龙无首，吉。
小象传
象曰：用九，天德不可为首也。
爻位
用九是乾坤两卦六爻皆变时所读的辞。
此爻变
六爻皆变，乾为天变为坤为地（第 2 卦）。对应的易林诗：焦氏易林·乾之坤。
理雅各英译（1882）
(The lines of this hexagram are all strong and undivided, as appears from) the use of the number NINE. If the host of dragons (thus) appearing were to divest themselves of their heads, there would be good fortune.
'The same NINE (undivided) is used' (in all the places of this hexagram), but the attribute of heaven (thereby denoted) should not (always) take the foremost place.
本卦
乾为天（第 1 卦），卦辞：乾：元，亨，利，贞。
上一爻：上九
经文依通行本，已与 Chinese Text Project（ctext.org）逐段比对。卦象是研读与自我反思的材料，不作吉凶断语，也不替代医疗、法律、财务等专业意见。