Approaching a wealthy man for provisions requires a delicate balance of respect, proof of merit, and perfect timing. When David's men reach out to Nabal, they carefully craft their request to be as polite and unobtrusive as possible.
Rather than demanding payment for their services, they invite Nabal to verify their claims with his own workers. They encourage him to ask his shepherds in Carmel, confident that the workers will confirm the truth: David's men had faithfully protected them and their flocks [מצודת דוד, שטיינזלץ, אברבנאל]. By relying on this positive testimony from Nabal's own staff, the messengers hope to earn his favor and be received with a warm welcome [רש״י, מצודת דוד].
The core of their appeal rests on the specific timing of their arrival. The primary approach among commentators is that they arrive during the sheep-shearing festival, a time traditionally marked by large feasts and celebration. Mentioning this festive atmosphere serves two distinct purposes. First, people are naturally more generous and open-hearted during a holiday, making them more inclined to help those in need [מלבי״ם, שטיינזלץ]. Second, since Nabal has already prepared a vast amount of food and drink for his shearers, providing for David's men would not force him to incur any special or additional expenses [רד״ק, אברבנאל]. Alternatively, another tradition suggests that this encounter takes place on the eve of the Jewish New Year, and the men are simply asking for food so they can properly celebrate the holiday meal [רש״י, אברבנאל].
Having established their merit and the ideal timing, they finally present their request. They ask Nabal to provide whatever he can comfortably spare, whether it be a small or large amount [מלבי״ם, מצודת דוד]. This is presented as a voluntary gift in return for the cooperation and protection they provided to his shepherds [שטיינזלץ]. To soften the request even further, they conclude with deep humility, respectfully referring to themselves as Nabal's servants [מצודת דוד].