What is the ruling on an engagement party, and what is meant by the Hadith: "Announce the marriage, and keep the engagement secret"?

The engagement party where the suitor meets his fiancée before the marriage contract is forbidden, as she is considered a stranger to him. Thus, it is not permissible for him to be alone with her, shake her hand, or see her adorned. However, after the marriage contract, it is permissible to hold a party to announce the marriage, based on the Prophet's (peace be upon him) saying: "Announce the marriage," while ensuring it is free from forbidden acts such as intermingling (free mixing of unrelated men and women) and unlawful singing. It is permissible for women to use the duff (a type of tambourine). The hadith "Keep the engagement secret and announce the marriage" is weak and unsound.