en_tn/2ch/26/20.md

behold, he had become leprous

The word "behold" here shows that the priests were surprised by what they saw.

They quickly drove him out of there

"They quickly forced him out of there" or "They quickly made him leave"

Yahweh had struck him

This speaks of Yahweh making him sick as if Yahweh had hit him. AT: "Yahweh had made him ill" (See: rc://en/ta/man/translate/figs-metaphor)