The moral decline of the nation has reached a breaking point, echoing one of the darkest chapters in their history. Such extreme behavior carries a warning of inevitable divine justice.
The Israelites have fallen into a deep state of wrongdoing. This depth is not a physical measure, but a description of their extreme and constant offenses. Just as something physically deep is entirely out of reach, actions pushed to the absolute limit are considered deeply entrenched [מצודת ציון]. The people have strayed far from the proper path [אבן עזרא, רד״ק], actively attempting to hide their plans from God [מלבי״ם], and completely ruining their moral standing.
This total corruption mirrors the terrible days of Gibeah. The primary approach among commentators is that this refers to the horrific crime involving the concubine at Gibeah of Benjamin. During that tragedy, the tribe of Benjamin protected offenders who committed atrocities comparable to those of Sodom. This event left a permanent mark on the national memory, as the entire nation knew of the crime and carried the shame of its aftermath [ביאור שטיינזלץ]. Much like the tribe of Benjamin defended the guilty in the past, the current generation protects its own wrongdoers. False prophets help them do this by offering empty promises of peace [מצודת דוד, אברבנאל]. As a result, the people are guilty of a double failure, committing offenses both against their fellow human beings and against God [מלבי״ם]. Alternatively, another perspective suggests that the historical comparison points to Gibeah of Saul. In this view, the comparison represents the era when the people rebelled against the word of the prophet and demanded a human king to rule over them [רש״י].
Because of this deep-rooted corruption, the nation faces unavoidable consequences. God will remember their wrongdoing and address their sins. Their actions will not simply be forgotten; He will hold them fully accountable and deliver the punishment their deeds require [מצודת דוד, מלבי״ם, ביאור שטיינזלץ].