We may rightly claim Ezekiel to be the founder of Judaism, with its transcendent conception of Jehovah and its great attention to ceremonial detail, and we are bound therefore to recognise in Ezekiel a falling off from the ideals of the pre-exilic Prophets; he is a prophet in priest's clothing. Yet it may be questioned whether the idealistic teaching of the Prophets could have been preserved through the periods of the Exile and the Restoration, without this formal process. An outer husk of formality had to develop in order that the living kernel might be protected during the critical years when Persia, Greece, and Rome were to press their alien ideas upon this people. It has been well for the world that Ezekiel clothed the Prophets' teaching in the resisting garments of Judaism. The Exile could not fail to leave upon the Jewish nation an imperishable mark, and they emerged from that trial a different people. It was a shock that brought a repentance the Prophets had often laboured for in vain, and this repentance was marked by the initiation of many new movements in thought, and by a more stringent and solemn observance of their peculiar institutions. Probably in that alien land many of the Jews adopted the customs of their conquerors, since it is estimated that not more than a small fraction returned to Palestine. This defection would impress upon those who remained faithful the necessity for a strict policy of separation, and from this time certain institutions which had been inherited from ancient Semitic practice received a new meaning. Chief among these may be noticed the observance of the Sabbath, and the rite of circumcision. The observance of a certain day as sacred to the gods is a custom that is found in nearly all early religions, and there are traces of such an observance in the Babylonian religion. We do not find however in the historical books of the Bible that mention of the Sabbath which would be expected, if it was observed with the strictness common after the Exile. There are traces of an observance, not strictly defined, save that it is in association with the new moon feasts, and is combined with social relaxation (2 Kings iv. 22, 23; Hosea ii. 11; Amos viii. 5; Isa. i. 13). Even before the Exile however a more religious conception had arisen (Jer. xvii. 19-27), and is even then referred to as an earlier command. The change after the Exile was towards an ever increasing strictness (Isa. lvi. 2, 4, 6; lviii. 13; lxvi. 23; Neh. xiii. 15-22). The rite of circumcision was by no means peculiar to the Jewish religion (Jer. ix. 25, 26), except perhaps in so far as it was performed in infancy: its origin and growth are very obscure. Its original significance was early lost and its interpretation was probably due to the Prophets themselves, who often referred to a spiritual circumcision, and thus made possible the full ceremonial interpretation which became so important a feature in later Judaism.