If Christ gave himself a human nature, then how does one distinguish his human nature from his divine nature?
Christ didn’t simply ‘put on’ a human nature, he was Fully God and Fully man.
He was born OF Mary, as her son, not born IN Mary.
... and Mary was born of her own mother in turn.
Jesus Christ was born not subject to original sin. He was fully God. He was also fully human and therefore subjected to temptation, of this scripture amply informs us. He did not, however, sin. Therefore he was sinless in human form, without blemish, within all the Old Testament strictures pertaining to sacrifice.
His mother, Mary, found favor with God, of this scripture also informs us. All else is elaborate medieval speculation centering upon the mechanics of physical conception, but ultimately concluding that God can protect a child from a mother’s sin nature in the womb.
Jesus was protected frpm Mary’s sin nature in the womb.