'Happens' in the Bible

"If a man has two wives, [and] the one [is] loved and the [other] one [is] disliked and the one loved and the one that is disliked have borne for him sons, if it happens [that] the firstborn son {belongs to the one that is disliked},

"If it happens [that] a young woman, a virgin, [is] engaged to a man, [and] a man finds her in the town and lies with her,