This question already has an answer here:

I once heard a rabbi say that there is an ancient custom (i.e. minhag) to insert a paper with ones bakashos (requests) in between the stones of the western wall.

  1. Where is the source of this minhag?

  2. Is it a minhag or halachah?

marked as duplicate by Shokhet, Double AA Nov 9 '14 at 18:07

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.

  • Since the old post didn't address this, I wonder how meaningful the act of placing prayers into crevices can be since "The Wall" is known to be part of the outer wall of the temple compound, not physically part of the temple. Also, the eastern wall that we observe today is actually an later addition to the original wall that is still underground. – JJLL Nov 10 '14 at 3:54
  • Any prayer is meaningful to the person who prays sincerely. Hashem hears prayer - all types. – Epicentre Nov 10 '14 at 4:56
  • It certainly isn't halacha – CashCow Nov 10 '14 at 15:41