To tremble at my words, to be careful in speech/ to be very anxious about/ worried about
He made sure to carry out the instructions or the things he heard. The matter was very important to him.
(“For all these things My hand has made, and so all these things came to be,” declares the LORD. “But to this one I will look: to the one who is poor and of a contrite spirit, and who trembles at My word.” — Isaiah 66:2)
Translation
Expression (Hebrew)
חָרֵד עַל דְּבָרַי, חָרֵד לְדַבֵּר
Definition (Hebrew)
הִקְפִּיד לְקַיֵּים אֶת הַהוֹרָאוֹת אוֹ אֶת הַדְּבָרִים שֶׁשָּׁמַע. הַדָּבָר הָיָה חָשׁוּב לוֹ מְאוֹד.
("וְאֶת כָּל אֵלֶּה יָדִי עָשָׂתָה וַיִּהְיוּ כָל אֵלֶּה נְאֻם ה' וְאֶל זֶה אַבִּיט אֶל עָנִי וּנְכֵה רוּחַ וְחָרֵד עַל דְּבָרִי"- יְשַׁעְיָהוּ סוּ ב)