《史记·八书·天官书》
按五行说，岁星于五方主东方，于五行中属木，于四季主春，于十天干为甲乙。
曰东方木，主春，日甲乙。
According to the Five Elements theory, Jupiter governs the east in the five directions, belongs to wood in the five elements, governs spring in the four seasons, and is Jia and Yi in the ten heavenly stems.