Proverbs 14:29 Kabbalah

אֶ֣רֶךְ אַ֭פַּיִם רַב־תְּבוּנָ֑ה וּקְצַר־ר֝֗וּחַ מֵרִ֥ים אִוֶּֽלֶת׃

He that is slow to anger is of great understanding; But he that is hasty of spirit exalteth folly.

Read kabbalistic (mystical) interpretation of Proverbs 14:29: and classical mystical sources.