Sanming TonghuiVol. 1, On the Nature and Fortune of the Sixty Jiazi (verdicts & remarks)
Ding Hai Earth is the open plains; it delights in Fire and Wood. Heavenly Officer, Fortune Star, Officer Noble, Virtue Combination (Harmony), Flat Head. Ding Hai is Earth at the Officer Stage. Wood cannot overcome it.
It disdains an excess of Metal and must obtain Fire to engender and rescue it for auspiciousness. It dreads the Wood of Ji Hai and Xin Mao.
The Essential Discourse on the Five Elements says: "The two Earths of Ding Hai and Geng Zi contain the numerical resonance of Metal, being firm within and harmonious without.
Those endowed with them possess steady resolve; if aided from below by the flourishing qi of Water and Fire, they can achieve great deeds, daring to act with authoritative and decisive fortitude."