The Heavenly Stem and Earthly Branch Assignment System
Na Jia means absorbing the stems. Developed by Jing Fang in the Han Dynasty, it assigns the Ten Heavenly Stems and Twelve Earthly Branches to each line, creating a precise temporal-spatial framework.
The Ten Stems (Jia through Gui) are assigned to trigrams by yin-yang and element rules, providing fine-grained analysis beyond the trigram level.
The Twelve Branches (Zi through Hai) are assigned to each line position. They carry Five Elements, directions, seasons, and zodiac signs.
Six Relatives are determined by comparing line branch elements with palace elements, creating five categories. This is the heart of Na Jia analysis.
Combining Stems and Branches creates the 60-term Ganzhi cycle. Each line receives a complete designation for timing and elemental interpretation.
纳甲完成后，每一爻的地支与月建（当前月份的地支）、日辰（当天的干支）进行比对，判断爻的旺衰。月建生扶则旺相、月建克制则休囚、月建直冲则月破。日辰对爻的影响次于月建但同样重要。旺衰判断是断卦的核心环节。