תְּחִלַּ֥ת דִּבְרֵי־פִ֖יהוּ סִכְל֑וּת וְאַחֲרִ֣ית פִּ֔יהוּ הוֹלֵל֖וּת רָעָֽה׃
The beginning of the words of his mouth is foolishness; and the end of his talk is grievous madness.
Read kabbalistic (mystical) interpretation of Ecclesiastes 10:13: and classical mystical sources.