Exodus 7:14

כבד — This word should be translated in the Targum by יקיר (his heart is hard — an adjective) and not by אתיקר (his heart has become Hard — a verb, as is given in some editions of Onkelos) because it is an adjective, just as (Exodus 18:18) “the thing is too heavy (כָּבֵד) for thee”.

וַיֹּ֤אמֶר יְהֹוָה֙ אֶל־מֹשֶׁ֔ה כָּבֵ֖ד לֵ֣ב פַּרְעֹ֑ה מֵאֵ֖ן לְשַׁלַּ֥ח הָעָֽם׃

And the Lord said to Moshe, Par῾o’s heart is hardened, he refuses to let the people go.