Deuteronomy 6:4

4.Hear, O Israel. When Moses proclaims that God is One, the statement is not confined to His sole essence, which is incomprehensible, but must be also understood of His power and glory, which had been manifested to the people; as though he had said, that they would be guilty of rebellion unless they abode in the One God, who had laid them under such obligations to Himself. Therefore he not only calls him Jehovah, but at the same time infers that He is the God of that people whom he addresses, “Thy God.” Thus all other deities are brought to nought, and the people are commanded to fly and detest whatever withdraws their minds from the pure knowledge of Him; for although His name may be left to Him, still He is stripped of His majesty, as soon as He is mixed up with a multitude of others. Thus He says by Ezekiel, (Ezekiel 20:39,) “Go ye, serve ye every one his idols;” in which words He not only repudiates all mixed worship, but testifies that He would rather be accounted nothing than not be worshipped undividedly. The orthodox Fathers aptly used this passage against the Arians; (280) because, since Christ is everywhere called God, He is undoubtedly the same Jehovah who declares Himself to be the One God; and this is asserted with the same force respecting the Holy Spirit.