אַל־תְּבַהֵ֥ל בְּרֽוּחֲךָ֖ לִכְע֑וֹס כִּ֣י כַ֔עַס בְּחֵ֥יק כְּסִילִ֖ים יָנֽוּחַ׃
Be not hasty in thy spirit to be angry; For anger resteth in the bosom of fools.
Read kabbalistic (mystical) interpretation of Ecclesiastes 7:9: and classical mystical sources.