Is the husband's message to his wife, whom he divorced with a single pronouncement of divorce for her to return to her home, considered a "revocation" (rajʿah), or is it necessary to have a new contract and dowry after her waiting period (ʿiddah) ends?

If a husband sends his divorced wife a message containing only the phrase "You are divorced," this statement is not considered a retraction (رجعة) on his part. If her waiting period ('iddah) has ended, he cannot take her back except with a new contract and a new mahr (dowry).