וַיַּשְׁלִ֙יכוּ֙ אִ֣ישׁ מַטֵּ֔הוּ וַיִּהְי֖וּ לְתַנִּינִ֑ם וַיִּבְלַ֥ע מַטֵּֽה־אַהֲרֹ֖ן אֶת־מַטֹּתָֽם׃
For they cast down every man his rod, and they became serpents; but Aaron’s rod swallowed up their rods.
Read kabbalistic (mystical) interpretation of Exodus 7:12: and classical mystical sources.