My short communication deals with the Disticha (twenty-one couplets of hexameters dedicated to Old- and New Testament episodes) attributed to Ambrose and first published by M. De La Bigne in 1589. This work represents a very interesting collection of tituli historiarum, that it to say, epigrams which aim to describe and explain pictured narratives with biblical theme. After having presented the text and the different scholarly positions on its paternity, I would like to discuss the complex theme of its relation with a putative iconographic model. As a second part of my communication, I would like to thoroughly analyse the distich II De La Bigne (21 Biraghi), and in particular the controversial image of John recubantem in pectore Christi (II , 1). This "ekphrastic" particular, which has no iconographic parallel until the 10th c., should not represent an argument for a lower datation (6th-9th c.) of the Disticha, since it finds some precise parallels in the Fathers of the fourth c., in Ambrose's treatises, and in the hymn Amore Christi nobilis attributed to the Bishop of Milan, whose authenticity is still discussed (Simonetti) but accepted by many (Bonato, Fontaine, Banterle). In the titulus as well as in the hymn, the image of John "reclining his head on Jesus' bosom" does not possess a primarily descriptive tone, but rather represents the spiritual inspiration which allowed John to write his Gospel and especially its prologue, as explained by Ambrose in the closing line (unde Deum Verbum assumpsit pietate fateri).