They knew that God is One, Only, Sovereign: "Hear, O Israel, the Lord our God is one God." It had been a hard lesson for Israel to learn. Centuries had passed before the nation had been purged of its idolatries. But the cleansing fires had done their work at last, and perhaps the world has never seen sterner monotheists than were the Pharisees of the time of Christ.[10] And He whom thus they worshipped as Sovereign they knew also to be holy: "The Holy One of Israel," "exalted in righteousness." True, Pharisaism had degraded the lofty conceptions of the great Hebrew prophets; it had taught men to think of God as caring more for the tithing of mint, and anise, and cumin than for the weightier matters of the law, judgment, mercy, and faith, making morality merely an affair of ceremonies, instead of the concern of the heart and the life. But, however Jewish teachers might blind themselves and deceive their disciples, the Jewish Scriptures still remained to testify of God and righteousness, and of the claims which a righteous God makes upon His people: "Wash you, make you clean; put away the evil of your doings from before Mine eyes; cease to do evil; learn to do well." Nor, accustomed though we are to think of the God of the Old Testament as stern rather than kind, were the tenderer elements wanting from the Jewish conception of Deity. Illustration is not now possible, but a very little thought will remind us that it is to the Hebrew psalmists and prophets that we owe some of the most gracious and tender imagery of the Divine love with which the language of devotion has ever been enriched.