Why did Mefivoshes say that Tziva can take the entire field?
Shabbos 56b: I was hoping for your return, and you treat me like this?! My complaints are not against you, rather, against He who returned you! He is called "Meriv Ba'al" in Divrei ha'Yamim I, 8:34, because he made a Merivah (quarrel) with his Master.
Malbim: He was so happy that David returned, he would not mind if Tziva took everything.
The coming verses discuss when David crossed the Yarden. Why was this Parshah (when he entered Yerushalayim) written out of place?
Malbim (31): It is written next to that of Shim'i, to show that David pardoned the sin of one who rebelled against him and cursed him, and improperly condemned one who sought his Shalom and honored [his father Yehonason's] Bris with him. 1
Me'iri (Yuma 22b): One who is merciful in a place proper for cruelty (against Resha'im who should be killed), that mercy is turned to cruelty on others. Refer to Shmuel I, 22:19:2:1.