How can a wife be taken back after a revocable divorce, and is it a condition for her to know or for there to be witnesses, especially if no prior divorce has occurred?

If a divorce occurs after consummation, is not for compensation, and has not completed three pronouncements, then it is a revocable divorce (ṭalāq rajʿī). Revocation occurs through the husband's statement, "I have taken back my wife," or similar explicit phrases, or through an act that implies revocation accompanied by intention, or through sexual intercourse. The wife's knowledge or consent is not a condition for its validity, and it is recommended to have witnesses for it.