I have a couple of questions regarding Mikhal the daughter of Shaul and her relationship with David.
1) In I Samuel 25:44 we find Mikhal being given as a wife to Palti son of Layish. Did this marriage take place before or after she became David's wife?
2) In II Samuel 6:23, after Mikhal rebukes David upon his dancing before the Ark, the verse states that Mikhal had no children. However, in II Samuel 21:8 we find that Mikhal had five children.
1) The commentaries understand that Mikhal was already David’s wife when she was given to Palti. This follows both the straightforward meaning of the verse “And Shaul gave Mikhal, his daughter, the wife of David, to Palti ben Layish who was from Galim” and the order of the events as recorded in the Book of Samuel – the verse stating she was given to Palti is I Samuel 25:44, while the verse stating that she was given to David as a wife is earlier - I Samuel 18:27. The Babylonian Talmud, tractate Sanhedrin, fol. 19b has a discussion of David’s relationship with Mikhal and Merav - two of Shaul’s daughters . As we see in I Samuel 17:25 it was at least claimed that whoever killed Galyat would be given the king’s (i.e. Shaul’s) daughter in marriage. After David slew Galyat, Shaul did offer Merav, his oldest daughter to David as a wife if David would continue to fight the “battles of God” - as we find in I Samuel 18:17. In I Samuel 18:19 we find the enigmatic verse “And it was at the time of Merav, the daughter of Shaul, being given to David – and she was given to Adriel the Meholat as a wife”. The Rabbis in Sanhedrin argue about whether David considered that he was also married to Merav, or only to Mikhal. Both agree, however, that he considered a marriage to have taken place between himself and Mikhal. Shaul did not consider what had occurred to be deemed a marriage in either the case of Merav or of Mikhal, hence he felt entitled to give both of them in marriage to someone other than David. In II Samuel 3:14-16 we find Mikhal being returned to David. According to the Rabbis in Sanhedrin (ibid.) in all the years Mikhal had been with Palt, Palti (who was very righteous) had not attempted to be intimate with her.
2) Various opinions are expressed. One opinion found in the Babylonian Talmud, tractate Sanhedrin, fol. 21a is that she had children before the incident in II Samuel 6:20-23 where she rebuked David. Another opinion focuses on the words in the verse “had no children until the day of her death” and states that she did have a child on the day of her death, i.e. she died in childbirth. Rabenu Yeshaya ben Mali of Trani (b. ca. 1200) in his commentary on this verse seems to take the straightforward approach that she never had children. An opinion is expressed in the Babylonian Talmud, tractate Sanhedrin, fol. 19b that the children mentioned in II Samuel 21:8 were actually Merav’s children – this would explain why the father is Adriel of Meholat who we know from I Samuel 18:19 to be Merav’s husband. Mikhal had raised Merav’s children and thereby merited that the verse treated them as if they were hers. According to the Talmud (ibid.), this teaches that whoever raises an orphan in their house is considered by the Torah as if they had given birth to that orphan.