This gesture expresses overcoming the world of appearance through enlightenment, as well as the enlightened state of mind for which samsara and nirvana are one. The nerve channel associated with the mind of enlightenment passes through the thumbs. Thus, joining of the two thumbs in this gesture is of auspicious significance for the future development of the mind of enlightenment.
It is the mudra of meditation, of concentration on the Dharma, and of the attainment of spiritual perfection. It indicates the perfect balance of thought, rest of the senses and tranquillity.