Sheep-shearing was a time of celebration, feasting, and generosity.
David also frames his request around service rendered: his men had been a wall of protection around Nabal's shepherds in the wilderness, like a proper king.
Nabal responds with contempt.
He compares David to a runaway slave (v. 10), which may also be a subtle jab at David having been Saul’s servant.
He will not give what is customary to men he claims not to know, but he obviously knows who David is.
David arms four hundred men and rides to destroy Nabal's household (vv. 12–13).
The insult strikes at David's identity and his men's honor.
David mistakenly takes matters into his own hands without first inquiring of the Lord.
Abigail acts without hesitation and without telling Nabal (vv. 14–19).
One of Nabal's servants brings her the report and names Nabal as the one at fault, saying that plainly, "he is such a worthless man that one cannot speak to him" (v. 17).
Abigail loads up tribute and goes to intercept David.
Abigail's speech is the theological center of the chapter (vv. 24–31), reminding David that the king is to inquire of the Lord and not waste himself on worthless men.