Following on the discovery in the BNE [National Library of Spain] of manuscript MSS/74—an extensive anthology of 16th century letters and mystic opuscules—it was possible to identify two of the three anonymous «alphabets» devoted to the love of God at the end of this compendium: in fact they are two alphabetical poems by Francisco de Osuna. An unpublished example of manuscript versions of the poems of Osuna, an Andalusian Franciscan, these alphabets present significant differences from the printed versions contained in the Second and the Fourth Spiritual Alphabets. A comparison of the two versions and a close analysis of these differences makes it clear that the poems circulated in oral and manuscript form among spiritual circles of a more or less alumbrado persuasion, and suggest the need to restate the question of the origins of the first four volumes of the Spiritual Alphabet, based on the prose glossa of the alphabetical poems. As for the third «alphabet», although it contains formal and thematic features which recall Osuna’s verses, we as yet lack sufficient evidence to categorically affirm his authorship.