וַיְהִ֗י בְּעֵ֥ת תֵּ֛ת אֶת־מֵרַ֥ב בַּת־שָׁא֖וּל לְדָוִ֑ד וְהִ֧יא נִתְּנָ֛ה לְעַדְרִיאֵ֥ל הַמְּחֹלָתִ֖י לְאִשָּֽׁה׃
But it came to pass at the time when Merab Saul’s daughter should have been given to David, that she was given unto Adriel the Meholathite to wife.
Tosefta Sotah
Similarly, you can say (2 Sam. 21:8), "And the five sons of Michal daughter of Saul that she bore to Adriel [son of Barzilai] the Mecholatite, etc." Here we find that [Saul] gave Michal to Adriel the Mecholatite. But did he not give her, rather, to Palti son of Laish from Gallim? For it says (1 Sam. 25:44), "And Saul gave Michal his daughter, the wife of David, to Palti son of Laish." Rather, the marriage of Michal is juxtaposed to the marriage of Merav (see 1 Sam. 18:19). Just as the marriage of Merav [was consummated] through sin, so too the marriage of Michal to Palti ben Laish [was consummated] through sin.