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.
Datum Target GD&T Training Definition. Geometric Dimensioning & Tolerancing GD&T Training. GD&T Training Definitions. Datum Target - is a specified point, line, or area on a part that is used to establish the Datum Reference Plane for manufacturing and inspection operations.