This question already has an answer here:

When did the use of two yuds becone a כינוי for the שם הוי"ה? Is this perhaps the two yuds of "יאהדונהי"? What's the source for using this abbreviation in place of other shemos in davening?

marked as duplicate by Double AA Jun 6 '17 at 14:14

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • Nice Q. Do you want to know in general how that "abbreviation" was created, or are you asking specifically why that's used in davening, only? If you're asking generally, please delete your last question. – DanF Jun 6 '17 at 13:56

Browse other questions tagged .