'Legally' in the Bible

to a virgin legally promised in marriage to a man {named} Joseph of the house of David. And the name of the virgin [was] Mary.

to be registered together with Mary, who was legally promised in marriage to him [and] was pregnant.

Jesus himself was about 30 years old when he began his ministry. He was (as legally calculated) the son of Joseph, the son of Heli,

Pilate told them, "Take him yourselves and pass judgment on him according to your own law!" The Jewish leaders replied, "We cannot legally put anyone to death."

So then, if Demetrius and the craftsmen who are with him have a complaint against anyone, the courts are in session and proconsuls are available; let them bring charges against one another there.

For example, a married woman is legally bound to her husband while he lives. But if her husband dies, she is released from the law regarding the husband.

He has qualified us [making us sufficient] as ministers of a new covenant [of salvation through Christ], not of the letter [of a written code] but of the Spirit; for the letter [of the Law] kills [by revealing sin and demanding obedience], but the Spirit gives life.

For if the message spoken through angels was legally binding and every transgression and disobedience received a just punishment,

But Jesus has now obtained a superior ministry, and to that degree He is the mediator of a better covenant, which has been legally enacted on better promises.