Sjoquist p. 33 Vajra Mudrā or Jñāna Mudrā or Bodhaśrī Mudrā
zhìquán yìn 智拳印
This gesture indicates supreme knowledge or wisdom. It is made by making a fist with the right hand but extending the first finger, and then grasping that finger with the left hand. The gesture is used in ritual more than art.