וּבְדַבְּר֣וֹ עִמִּ֔י כַּדְּבָרִ֖ים הָאֵ֑לֶּה נָתַ֧תִּי פָנַ֛י אַ֖רְצָה וְנֶאֱלָֽמְתִּי׃
And when he had spoken unto me according to these words, I set my face toward the ground, and was dumb.
Read midrashic interpretation of Daniel 10:15: and classical rabbinic exegesis.