Acknowledging God's kindness involves recognizing the moments He actively chooses mercy over strict justice. When a nation faces the threat of punishment, the withdrawal of divine anger is a deep display of this grace.
The imagery presents God actively restraining His anger. The primary approach among commentators is that He gathers and conceals His fury, bringing it inward and putting it away like something stored out of sight. By locking away this intense rage, God ensures it is never unleashed upon the people. This deliberate restraint is further seen as God steps back from His burning wrath, completely halting any outward expression of anger [מצודת דוד, ביאור שטיינזלץ].
There is a broad consensus [רד״ק, אבן עזרא, המאירי] regarding the exact nature of this withdrawal. Rather than the anger simply fading away on its own, God takes direct action against His own wrath. He actively pulls His anger back from its burning state, deliberately reversing its course so that it cannot flare up and strike the nation.