Ezekiel 43:6 - Ellicott's Commentary On The Whole Bible

I heard him speaking. — Although the pronoun is not expressed in the original, there can be no question that God Himself spoke directly to the prophet, as in Ezekiel 44:2; Ezekiel 44:5; Ezekiel 44:9, &c. “The man” is without the article in the Hebrew, which leaves it uncertain whether the same being is meant who had hitherto guided the prophet; but as measurements were also made by this guide (Ezekiel 47:3-5), he was probably the same.