A Thigh is a root or a base. Biblically, it is the groin, the place of a man’s future; his children, the “fruit” of his body.
The thigh is the place where oaths are made, the oath that God swore from the foundation of the earth and is in the process of being fulfilled in Jesus. When loins are discussed, it’s as though their descendants already exist. They become witnesses to the oath, the “covenant”.
Revelation 13:8 “the Lamb slain from the foundation of the world”.
The faithful believers are the descendants of Jesus, the children of God. Imagine, the number of descendants from the time of creation, all of which, from the first to the last, are witnesses to that oath.
In an oath, it means, “If you don’t keep this oath, my descendants will come and get you.”- in Revelation 19 Jesus is the Kinsman Redeemer whose job it is to take vengeance on the enemies of the righteous. Jesus is the Creator, the base (thigh), from which mankind springs, AS WELL AS the descendant of Himself, who fulfills His own oath. It was decided, and in Revelation 19, it is done (finished!) (By He who was the beginning of the oath- AND by He who completes the oath: the Alpha and Omega.
THE MENORAH
Metaphorically, The Menorah is the “family tree” of Jesus and His Saints, Jesus is the Base (the Thigh), the Root of Salvation.
The Hebrew word for “thigh” is “Yerech” (base)
The loins are the base (the root) and the branches are the descendants as on a family tree.
On the Menorah, the loins (base/yerech) has three legs (Like the Godhead), the center stem is Jesus, while Believers are the branches. 
The Menorah illuminates the world and sets it on fire with the virgin oil of the Holy Spirit.
