The pebble is a part of the stone, the symbol of the Self. It will make an imprint on my foot — a merging with the Beloved. The foot is a replica of the whole body, which will become impregnated with the Self.
Vaughan-Lee interprets a dream-pebble worn in the shoe as a Sufi-Jungian symbol of the Self progressively imprinting itself upon the whole person through bodily suffering and intimate contact.
, Catching the Thread: Sufism, Dreamwork, and Jungian Psychology, 1992thesis