Holding the ankh to the god meant, 'I bestow life upon the god'; or the gods held the sign before the king, meaning that they bestowed life on the king. So that sign means generative power.
Jung interprets the ankh as the primary symbol of generative and creative power, operating as a reciprocal transfer of life-force between deity and mortal, and identifies its structure with the rhythmic systole-diastole movement of psychic energy.
, Dream Analysis: Notes of the Seminar Given in 1928-1930, 1984thesis