וְלֹֽא־יָכְל֣וּ הַֽחַרְטֻמִּ֗ים לַעֲמֹ֛ד לִפְנֵ֥י מֹשֶׁ֖ה מִפְּנֵ֣י הַשְּׁחִ֑ין כִּֽי־הָיָ֣ה הַשְּׁחִ֔ין בַּֽחֲרְטֻמִּ֖ם וּבְכָל־מִצְרָֽיִם׃
And the magicians could not stand before Moses because of the boils; for the boils were upon the magicians, and upon all the Egyptians.
Read kabbalistic (mystical) interpretation of Exodus 9:11: and classical mystical sources.