In chapter 17 of Dan Brown's Origin, he mentions something called the Grishneshwar Temple Drop.
... the slideshow concluded with a deeply unsettling video of an Indian cleric dangling a tiny infant over the edge of a fifty-foot tower. Suddenly the cleric let go, and the child plummeted fifty feet, straight down into an outstretched blanket, which joyful villagers held like a fireman's net.
The Grishneshwar Temple Drop, Langdon thought, recalling that it was believed by some to bring God's favor to a child.
What is this ritual? I cannot find any reference to this online.