however , as it happened , the arab 7th-century conquest of the middle east did much to facilitate the spread of a uniform rabbinic judaism when the heads of the babylonian rabbinical academiesclosely allied with the abbasid caliphate in baghddattempted to standardize jewish law , custom , and liturgy in accordance with their own practiceswhich they set forth in their replies ( responsa ) to inquiries from diaspora communities .