This chapter aims to show how hermeneutics bridges gaps of religious belief and practice between monotheisms, fostering circulation of similar ideas to disveil scriptural knowledge about Adam’s divine gift of combining letters into names manifesting the true nature of God’s creatures. Here I consider part of an addition to Epistle 50 of the Ikhwān al-Ṣafā’ (the Brethren of Purity). They are the authors of an encyclopaedia that recent scholarship dates at the first half of tenth century at latest. Epistle 50 deals with various kinds of administration or (or “proper attitudes”) toward body and soul. The addition is found in the MS Istanbul Esad Efendi 3638 (1287 A.D.). It is an esoteric text aiming to explain the inner meaning of the story of Adam. The final part approaches God’s bestowal of language to Adam, and the corruption of language after Adam’s fall. Numerous elements are added to the Qur’anic tale of sura 2, vv. 31-37 that differ from the biblical account in <em>Genesis</em>. First, I compare this chapter with the views about divine language of the Spanish mystic and thinker Abraham Abulafia (1240-1291 [?]), who grounded his kabbalistic view on divine language. My comparison moves from how the Arabic text may be better understood with help from Walter Benjamin’s article <em>On Language as Such and on the Language of Man</em>, likely influenced by researches of Gershom Scholem on the same topic. Despite the noticeable differences between them, the historical proximity of the anonymous author of the addition and Abulafia legitimates their comparison; we have a collateral evidence of the circulation of these ideas in the Muslim and Jewish contexts and between the Muslim East and al-Andalus. Second, as is known, Abulafia developed his theories on the basis of the first Judaic script on this topic, the ancient <em>Sefer yeṣirah</em>. Common issues between the Arabic addition and the <em>Sefer</em> demonstrate the circulation of similar ideas in Muslim and Jewish esoteric contexts. Third, ideas common to the Ikhwān al-Ṣafā’ and the commentaries of Dunash ibn Tamīm and Shabbetay Donnolo on the <em>Sefer yeṣirah</em> open a debate on the spread of the encyclopaedia in the Southern Italian scholarly milieu and bring further elements in favour of the Fāṭimid commitment of the Brethren of Purity.
