Charles Ellicott Commentary Ezekiel 28:6

"therefore thus saith the Lord Jehovah: Because thou hast set thy heart as the heart of God," — Ezekiel 28:6 (ASV)

Set thine heart as the heart of God. —The same expression as in Ezekiel 28:2. (Compare to Obadiah 1:3, “The pride of thine heart hath deceived thee.”) The meaning is plain: you have entertained thoughts and purposes fitting only to the Supreme.