(5) He tarried longer.—No cause is assigned for this, and various conjectures have been made. The simplest explanation may be drawn from the fact that, in 2Samuel 20:8, Amasa is met on his return at Gibeon. He had therefore gone quite out of the bounds of Judah into Benjamin, and had consumed more time in consequence of exceeding his instructions. The fact suggests great doubt of his fitness for the place David had promised him. Joab appears to insinuate (in 2Samuel 20:11) that Amasa was not really loyal.

20:4-13 Joab barbarously murdered Amasa. The more plot there is in a sin, the worse it is. Joab contentedly sacrificed the interest both of the king and the kingdom to his personal revenge. But one would wonder with what face a murderer could pursue a traitor; and how, under such a load of guilt, he had courage to enter upon danger: his conscience was seared.He tarried - The cause of Amasa's delay is not stated. It may have been the unwillingness of the men of Judah to place themselves under his orders, or it may have been caused by a wavering or hesitation in loyalty. This last is evidently insinuated in 2 Samuel 20:11, and no doubt this was the pretext, whether grounded in fact or not, by which Joab justified the murder of Amasa before David. 4. Then said the king to Amasa, Assemble me the men of Judah within three days—Amasa is now installed in the command which David had promised him. The revolt of the ten tribes, probably, hastened the public declaration of this appointment, which he hoped would be popular with them, and Amasa was ordered within three days to levy a force from Judah sufficient to put down the insurrection. The appointment was a blunder, and the king soon perceived his error. The specified time passed, but Amasa could not muster the men. Dreading the loss of time, the king gave the commission to Abishai, and not to Joab—a new affront, which, no doubt, wounded the pride of the stern and haughty old general. But he hastened with his attached soldiers to go as second to his brother, determined to take the first opportunity of wreaking his vengeance on his successful rival. Either because the people, being wearied out by the late civil war, were not forward to engage in another; or because the soldiers had more affection to Joab than to their new general, to whose ill conduct possibly they might impute their unsuccessfulness in the last battle; or because Amasa for his own interest might seek delays, to render himself more necessary and useful to the king, and to keep up his honourable and profitable employment, which is the common policy of such men.

So Amasa went to assemble the men of Judah,.... To gather, them together out of their several tribes, and bring them to Jerusalem:

but he tarried longer than the set time which he had appointed him: than the three days; whether this was owing to the remissness of Amasa, or the unwillingness of the people to serve under him, who had been Absalom's general in the late rebellion, or not having time sufficient allowed him, is not certain.

So Amasa went to assemble the men of Judah: but he tarried longer than the set time which he had appointed him.