# Her prophets have painted them over with whitewash

"It is like her prophets have painted over their sins with whitewash" or "Their prophets try to hide these evil things"

# whitewash

This is a solution that is painted on things to make them white that is similar to white paint.

# their seers

The word "their" refers to the priests (Ezekiel 22:26) and princes (Ezekiel 22:27).