I've read in many places in the Pali canon that the Buddha will answer a question if asked three times even if the Buddha is extremely reluctant to give the answer. For instance in the Talaputa Sutta the Buddha is asked by Talaputa ,the leader of a troupe of actors, about what will happen to actors when they are reborn. The Buddha clearly doesn't want to say (it's not good news) but Talaputa really pushes it and asks him three times
"Enough, headman, put that aside. Don't ask me that."
A second time... A third time Talaputa, the head of an acting troupe, said: "Lord, I have heard that [...] What does the Blessed One have to say about that?"
The Buddha gives in and delivers the bad news.
But what is the origin of this questioning technique? Why does he always give an answer if pushed like that? Was it a traditional thing in Indian society at that time or was it just a thing with the Buddha? I've only read this in the Pali canon. Does it crop up in other texts and traditions too?