Văn bản tướng pháp/phổ lục về hạc: khí kim–hỏa, chu kỳ biến hình (16/60/1600 năm), dấu hiệu tiên cầm. Thu vào kinh tịch–phổ lục; là mẫu “tướng cầm” trong tạp phương thuật.
Ứng dụng: Tướng cầm, biểu tượng tiên hạc; so sánh với các sách tướng mã/ngưu/bối.
托名周代仙人浮丘公（浮丘伯）所授王子乔之鹤经，唐宋类书、王安石跋本等有传。论鹤为「阳鸟而游于阴」，因金气依火精自养（金九火七），故七年小变、百六十年大变、千六百年形定：顶赤、飞薄云汉、鸣中律、不食生物、毛白如雪等。以鹤为仙禽、长寿与羽化象征，将物候、五行与修仙阶段对应，属相物/相禽术与神仙博物传统。
⚡ Ứng dụng: 仙禽象征、五行生养与长生阶段；鹤喻修道「形定」与纯阳之体。
🔗 Liên quan: 相鹤；列仙传王子乔；抱朴子
Outer form is a lawful expression of inner vital quality: if a creature’s morphology tracks longevity, purity, and rank of qi, then careful physiognomy can rank living beings by essence grade. The text proves a general method—read the visible to grade the invisible—that underwrites later human and destiny physiognomy.
1) Apply form→essence logic cautiously in BaZi: body/face signs as weak corroboration of chart constitution, never as sole proof. 2) Grade day-master ‘bone’ (structure strength) the way 相鹤 grades frame and cry. 3) In cultivation, choose methods matched to constitution grade (gentle vs intense). 4) Train observational discipline: note co-occurring signs, discard single-feature fetish.
Compared with 人物志, which ranks human talents by psychology and virtue, 相鹤经 ranks life-force by animal morphology. It supplies the outer-form premise that later 相学 extends to humans, but stays zoological and vital rather than political or ethical.