Immediately after physical desire is satisfied, a sharp and extreme emotional reversal takes place. Amnon's obsessive passion vanishes entirely, replaced by a fierce and burning hostility that is even stronger than the initial feeling. This sudden shift from love to hatred can be understood through several approaches. Psychologically, Amnon's initial emotion was never true or deep love, but merely animalistic lust. Once that physical urge was fulfilled, the false love disappeared [מלבי״ם]. Furthermore, committing a disgraceful act naturally brings about deep regret. Recognizing the terrible nature of his actions, Amnon could no longer bear to look at Tamar, as her presence served as a constant reminder of his crime. The memory of his fake love disgusted him, and he projected his own regret and self-hatred directly onto his victim [מלבי״ם, אברבנאל].
Other perspectives suggest that the sudden hatred was triggered by Tamar's reaction. It is highly likely that she fought back fiercely, resisted with all her strength, or shouted harsh rebukes during the ordeal, which provoked his intense anger and hostility [רלב״ג, מצודת דוד]. Alongside these natural explanations, ancient sages offer an account of a physical injury acting as the source of the hatred. According to this view, a miraculous divine punishment occurred during the act, causing a severe physical wound that left Amnon permanently maimed. The resulting pain and deformity are what truly ignited his rage [רש״י, רד״ק, חומת אנך, אברבנאל].
Driven by this intense hatred, Amnon demanded that Tamar leave immediately, refusing to let her stay in his home for even one more moment [מצודת דוד, ביאור שטיינזלץ]. He threw her out with total contempt. Commentators point out that this sudden expulsion in broad daylight, and indeed the entire sequence of events, was carefully orchestrated by God. By forcing her out during the day, a secret crime was dragged into the open, greatly magnifying the public disgrace [מצודת דוד, רד״ק, אברבנאל]. This public exposure was specifically designed to incite Absalom's hatred, ultimately driving him to seek revenge and murder Amnon. This chain of events served as the realization of a divine plan to punish David for his past actions involving Bathsheba and Uriah. Operating on the principle of measure for measure, a sexual sin led directly to bloodshed, fulfilling the prophetic decree that violence would never depart from David's family [רד״ק].