John Gill Commentary 2 Samuel 19:30

"And Mephibosheth said unto the king, yea, let him take all, forasmuch as my lord the king is come in peace unto his own house." — 2 Samuel 19:30 (ASV)

And Mephibosheth said to the king, yes, let him take all, &c.] The whole estate, as David had given it to him; he was content that that last grant should stand:

because my lord the king has come again in peace to his own house; his palace in Jerusalem; This was a strong expression of affection for him, and loyalty to him.

(Solomon used a similar test to determine which woman's baby was alive. ( 1 Kings 3:16–28). He purposed the baby be cut in two to reveal who the real mother was. Likewise, David suggests the property should be divided between Ziba and Mephibosheth to determine the true loyalty of the latter. (2 Samuel 19:29 2 Samuel 19:30) Editor.)