The Dhyana mudra is the gesture of meditation and of the concentration of the Good Law.
The two hands are placed on the lap, right hand on left with fingers fully stretched (four fingers resting on each other and the thumbs facing upwards towards one another diagonally), palms facing upwards; in this manner, the hands and fingers form the shape of a triangle, which is symbolic of the spiritual fire or the Triratna (the three jewels).
The Dhyana mudra is used in representations of the Sakyamuni Buddha and Amitabha Buddha. Sometimes the Dhyana mudra is used in certain representations of Bhaisajyaguru as the Medicine Buddha, with a medicine bowl placed on the hands. It originated in India most likely in the Gandhara and in China during the Wei period. The Dhyana mudra was used long before the Buddha as yogis have used it during their concentration, healing, and meditation exercises.
It is heavily used in Southeast Asia in Theravada Buddhism; however, the thumbs are placed against the palms.
(Dhyana mudra is also known as Samadhi mudra or Yoga mudra; Japanese: Jo-in, Jokai Jo-in; Chinese: Ding Yin.)