The rebuilding of the wall surrounding Jerusalem triggers a fierce and escalating reaction from the enemies of the Jews. Sanballat's response is not a sudden outburst, but rather a developing process of rage that builds from within before spilling out into the open.
The primary approach among commentators notes a clear progression in his hostility. Initially, his fury is entirely internal. He experiences a profound distress in his heart over the construction, harboring a hidden anger so intense that it likely causes his face to change color [מלבי״ם].
This internal buildup cannot remain contained. His anger soon transitions from a hidden emotion into a visible reality as he begins to openly display his rage, allowing his frustration to show. Finally, this visible anger boils over into direct action. Moving beyond mere feelings and outward displays of temper, Sanballat takes the practical step of actively mocking the Jews [מלבי״ם].