D'vekut means "sticking to God." It is like being cozy with God, snuggling with God. That is what people are getting into when they are putting on the t'fillin and wrapping themselves in the tallit. They are experiencing closeness through these holy things. Perhaps you have seen Catholics kissing their rosaries or a priest kissing the stole before he puts it on. It is like saying, "I am now surrounding myself with and putting my aura in touch with God."
— Zalman Schachter-Shalomi, Wrapped in A Holy Flame