From the First Book of Samuel, we are told:
1 Samuel 25:44: "Now Saul had given Michal his daughter, David’s wife, to Palti the son of Laish, who was from Gallim."
Was this lawful in Israel? Could a father, even if king, give his married daughter to another man, and worse, without the consent of the husband? (In 1 Sam. 18:20 we read that Michal loved David.)
NOTE: Of course, Saul may have considered David an outlaw. Does it matter?
Radak addresses this question thoroughly, but in Hebrew. I struggle with the translation, but here is a basic summary.
Apparently Saul forced a divorce of Michal from David. If David considered it legal, he would not have taken Michal back. That would have been unlawful.
Then David sent messengers to Ish-bosheth, Saul’s son, saying, “Give me my wife Michal, for whom I paid the bridal price of a hundred foreskins of the Philistines.” (2 Sam. 3:14, ESV)
David asking for Michal indicates that David consider the divorce forced by Saul to be illegal and his marriage to Michal still binding.
Did Saul have a legal right to give David's wife away (1 Sam. 25:44)?
No.
Deuteronomy 24:
1 If a man marries a woman, but she becomes displeasing to him because he finds some indecency in her, he may write her a certificate of divorce, hand it to her, and send her away from his house.
David had never issued this certificate of divorce.
Exodus 20:
14 You shall not commit adultery.
Leviticus 20:
10 “’If a man commits adultery with another man’s wife—with the wife of his neighbor—both the adulterer and the adulteress are to be put to death.
Isaiah 50:
1a This is what the LORD says: “Where is your mother’s certificate of divorce with which I sent her away?
David didn't write the divorce paper. Saul had to right to give his wife away.
King Saul was not above the law, Deuteronomy 17:
18 When he takes the throne of his kingdom, he is to write for himself on a scroll a copy of this law, taken from that of the Levitical priests.
Saul may have considered David an outlaw. Does it matter?
No. Everyone had to follow the Law.
I'm going to go against the other answers and say yes. Or at least it's not the only time we see a father having his daughter remarry without consulting her husband, which makes me think that legally it was something Saul could have done.
15 After a while, at the time of wheat harvest, Samson went to visit his wife with a kid; and he said, “I will go in to my wife in the chamber.” But her father would not allow him to go in. 2 And her father said, “I really thought that you utterly hated her; so I gave her to your companion. Is not her younger sister fairer than she? Pray take her instead.”
Also, Saul was the king. I'm pretty sure that he could change the law if he wanted.
Was he morally correct? No, but I believe that he wasn't breaking the law.
