be at (someone's) feet
To be enthralled with or captivated by someone. Both students and faculty members are at that renowned professor's feet.
at someone's feet, be
Also, sit at someone's feet. Be enchanted or fascinated by someone, as in Dozens of boys are at her feet, or Bill sat at his mentor's feet for nearly three years, but he gradually became disillusioned and left the university . [Early 1700s] For a quite different meaning, see under one's feet.