This prayer concludes the second volume of the late Renaissance medical tome Opera Omnia by Abraham Zacutus Lusitanus (Abraham Zacuto Ⅳ), published posthumously in 1644. While his Peroratio (Conclusion) is addressed to the critical reader, I think it is crucial to read it in the context of his life as a “New Christian,” i.e., a Portuguese-Jewish physician and converso, ever vulnerable to the attention of the Inquisition or from others who might profit or take petty pleasure in his downfall. . . .