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.
The North American Datum (NAD) is the datum now used to define the geodetic network in North America.A datum is a formal description of the shape of the earth along with an anchor point for the coordinate system.he North American Datum of 1983 is based on a newer defined spheroid (GRS 80); it is an Earth-centered (or  geocentric ) datum having no initial point or initial direction.