This paper traces the history and evolution of humanist re-use of the first couplet of Propertius’s elegy 2, 2, from Gregorio Tifernate’s Poemata to the end of the Quattrocento. Continued re-use of the couplet, or of its constituent elements, make it a veritable commonplace at a time when collections of loci communi were first coming into existence as ordered and consciously prepared works. The attraction of this particular couplet from Propertius was enhanced considerably by a parallel use in the Petrarchan vernacular love poetry tradition. This poetic commonplace became so well established that its very language appears in Christian moral poetry from the period, as evidenced by an example taken from Baptista Mantuanus’s collection of eclogues entitled Adulescentia. The commonplace established by Quattrocento elegiac poets thus became a weapon in the arsenal of edifying Christian poetry, whose authors redeployed elegiac language in their criticism of mankind’s excessive devotion to earthly passions.