Why did David say "Amarti"?
Malbim: David recognized that Tziva slandered him, but we do not retract the king's word. 1 Rather, he explained his words; he intended that they be partners in the field. "Amarti" - this was my intent. Also, it is not improper to give half to Tziva and his sons, who worked the field. He is like a sharecropper, who gets half. 2
What is the source of this? Even Achashverosh said so only about a document stamped with the king's signet (Esther 8:8)! David retracted several matters, e.g. his Shevu'ah to kill Naval, his exile of Avshalom and refusal to see him, his instruction to Itai to go back
What were the consequences of David's ruling?
Radak: They will divide the entire inheritance.
Radak citing Shabbos 56b: When David said that Tziva will split the field with Mefivoshes, a Bas Kol announced that [Midah k'Neged Midah, David's grandson] Rechav'om and Yarov'om (his slave) will split the kingdom of Yisrael.
