Exodus 10:2

התעללתי means I HAVE MOCKED, as in, (Numbers 22:29) “Because thou hast mocked (התעללת) me”; (I Samuel 6:6) “Indeed, when he mocked (התעולל) them”, which, also, is said in reference to Egypt. It is not an expression denoting doing and action, for were this so it should have written עוללתי, similar to (Lamentations 1:22) “And do (עולל) unto them as thou hast done (עוללת) unto me”, and to (Lamentations 1:12) “which he has done (עולל) unto me”.

וּלְמַ֡עַן תְּסַפֵּר֩ בְּאׇזְנֵ֨י בִנְךָ֜ וּבֶן־בִּנְךָ֗ אֵ֣ת אֲשֶׁ֤ר הִתְעַלַּ֙לְתִּי֙ בְּמִצְרַ֔יִם וְאֶת־אֹתֹתַ֖י אֲשֶׁר־שַׂ֣מְתִּי בָ֑ם וִֽידַעְתֶּ֖ם כִּי־אֲנִ֥י יְהֹוָֽה׃

and that thou mayst tell in the ears of thy son, and of thy son’s son, what things I have done in Miżrayim, and my signs which I have done among them; that you may know that I am the Lord.