What is the significance of position of fingers in Jesus' hand as shown in his images? In most of the visual images of Jesus – both in picture and sculpture forms – fingers of His right hand, raised in blessing, follow a particular arrangement. Is there any significance to that arrangement? Have different Churches including the Catholic Church given official recognition to its  interpretation?
From: What does this hand gesture mean in Icons? (Wordpress.com)


  The fingers spell out “IC XC”, a widely used four letter abbreviation
  of the Greek for Jesus (IHCOYC) Christ (XPICTOC). It is by the name of
  Jesus that we are saved and receive blessings: “At the name of Jesus
  every knee should bow, of things in heaven, and things in earth, and
  things under the earth;” (Phil 2:10).


I am not Orthodox but have learned a lot about that faith, the local priest here has said the same thing.

From the Orthodox Church of America site, "Placement of fingers in icons," I would assume an authoritative source.

You see this in a lot of Eastern Orthodox icons: