The outbreak of Absalom's rebellion against his father, David, is carefully timed and masked by a religious excuse. The timing of this uprising, occurring at the end of a forty-year period, is a subject of significant discussion. The primary approach among commentators views this as a profound historical and spiritual milestone: exactly forty years had passed since the Israelites first asked the prophet Samuel for a king. This specific timeframe highlights the direct connection between that original request and the current tragedy, showing how the desire for a monarch ultimately devolved into rebellion, bloodshed, and royal humiliation [רש״י, מצודת דוד, רד״ק, ביאור שטיינזלץ].
Other perspectives treat this timeframe more literally. It may mark forty years since the Israelite monarchy began with the anointing of Saul [רלב״ג], or forty years into David's own reign [רלב״ג, מלבי״ם, אברבנאל]. Operating under the latter assumption, Absalom realized his father was aging and feared David might soon crown Solomon. To prevent this, Absalom acted swiftly just before the fortieth year concluded [מלבי״ם]. Furthermore, Absalom might have been aware of a prophecy limiting David's rule to forty years, leading him to conclude that the time had arrived for the kingship to transfer to him [רלב״ג]. Additional interpretations suggest the forty years count from the time David parted ways with Saul, or that it simply reflects Absalom's own age [ביאור שטיינזלץ, אברבנאל].
To leave the capital city of Jerusalem without arousing suspicion, Absalom requests permission to fulfill a personal vow. He brilliantly disguises his political conspiracy as an act of innocent religious devotion, possibly claiming he needs to complete a Nazirite vow [ביאור שטיינזלץ]. During this era, before the permanent Temple was built in Jerusalem, it was entirely permissible to offer sacrifices on private altars anywhere in the land [רלב״ג, רד״ק]. This legal reality provides Absalom with the perfect cover to travel to a calculated destination.
The decision to travel specifically to Hebron is highly strategic. From a religious standpoint, Hebron likely hosted a central public altar where Absalom could isolate himself and pray to God for success in claiming his father's throne [רלב״ג, מצודת דוד, אברבנאל]. However, his true motives are deeply political. Most commentators agree that Absalom chose Hebron because it was the very place where David's own kingship first began and flourished. Absalom believed the location itself possessed a special power or omen that would guarantee his success [רלב״ג, רד״ק, אברבנאל]. Beyond its mystical appeal, Hebron was the historical capital of the tribe of Judah. Absalom calculated that if he could win over the people of Hebron and crown himself there, the rest of the Israelite tribes would see that the central city had accepted him and would naturally follow suit [מלבי״ם, אברבנאל].
An alternative Midrashic approach suggests that Absalom never actually intended to offer his sacrifices in Hebron itself. Instead, he traveled there merely to obtain the region's famously fat and high-quality sheep for his offerings. However, commentators note that this explanation is difficult to support based on the plain meaning of the text, which explicitly states the sacrifice itself would take place in Hebron, rather than simply sourcing the animals from there [רש״י, רד״ק, אברבנאל].