 It often overlaps with the force of teyolía which was often considered both an animating force (soul) and the physical heart in various Mesoamerican cultures.The root “tona” acts as a verb to mean "to irradiate or make warm with sun”.In the Ancient Nahuatl belief, the tonalli is bestowed upon a child in utero by the aged deities known as Ometecuhtli and Omecihuatl, or the “Lord and Lady of Duality”.