What is the symbolism for Carmelite Monks and Nuns kissing the floor?
Carmelite Friars and Nuns are not the only ones who kiss the floor. It is also a Franciscan tradition and several other religious orders and congregations.
It is a sign of reverence for the sacred space where God dwells, usually the chapel or church. It comes from the scriptures themselves where Moses and other prophets took off their shoes and prostrated themselves before the Lord.
I believe it was also done at the chapter of faults by the one being corrected, as a sign of humility.
I don’t know if the Carmelites kissed the floor or prostrated themselves at the chapter of faults. Franciscans didn’t prostrate. Franciscans never had a chapter hall. That was forbidden by St. Francis. They kissed the floor and knelt upright. I believe that Benedictines prostrated. I know that they had a chapter hall. The Cistercians, Trappists and other ancient observances of the Benedictine traditions probably still have a chapter hall.