'Son in law' in the Bible

And David said unto Saul, Who am I? and what is my life, or my father's family in Israel, that I should be son-in-law to the king?

And Saul said, I will give him her, that she may be a snare to him, and that the hand of the Philistines may be against him. Therefore Saul said to David a second time, you shall this day be my son-in-law.

And Saul commanded his servants, saying, Talk with David secretly, and say, Behold, the king has delight in you, and all his servants love you: now therefore be the king's son-in-law.

And Saul's servants spoke those words in the ears of David. And David said, Does it seem to you a light thing to be a king's son-in-law, seeing that I am a poor man, and lightly esteemed?

And when his servants told David these words, it pleased David well to be the king's son-in-law: and the appointed days were not expired.

Therefore David arose and went, he and his men, and slew of the Philistines two hundred men; and David brought their foreskins, and they gave them in full number to the king, that he might be the king's son-in-law. And Saul gave him Michal his daughter as his wife.

Then Ahimelech answered the king, and said, And who is so faithful among all your servants as David, who is the king's son-in-law, and goes at your bidding, and is honorable in your house?