Jacob's thigh was disabled by the Angel, to show the patriarch that his prevalence was through his faith and prayer, not through force, Genesis 32:25-31. Smiting the thigh was a gesture of self-condemnation and grief, Jeremiah 31:19 Ezekiel 21:12.
In general, a datum is a base elevation used as a reference from which to reckon heights or depths. A tidal datum is a standard elevation defined by a certain phase of the tide.
More broadly, a vertical datum is the entire system of the zero elevation surface and methods of determining heights relative to that surface. Over the years, many different types of vertical datums have been used. The most predominant types today are tidal datums and geodetic datums.Tidal datums are determined by averaging the level of water at a tide gage over time.ver the years, many different types of vertical datums have been used. The most predominant types today are tidal datums and geodetic datums. Tidal datums are determined by averaging the level of water at a tide gage over time.