One of the most famous works of aljamiado literature (literature in Spanish in Arabic script) is the Poem of Yusuf (“Poema de Yúçuf” in Spanish). The poem was written by an anonymous Morisco poet at the end of the XIII – the beginning of the XIV centuries. The poem is based on the most common plot among the Moriscos – the twelfth sūrah of the Qur'an. The poem includes a scene of lament at the grave, which is not found either in the Qur'an or the Old Testament. Researchers of the middle nineteenth century considered the scene original. However, later it was defined that the scene had appeared due to the influence of the Jewish apocrypha. Modern researchers called into question the originality of the scene and the poem itself. Nevertheless, in the lament scene, we can trace not only the influence of the Qur'an or the Old Testament Apocrypha, but also the traditions of pre-Islamic Arabic poetry [A1], which were developed in Al-Andalus. The objective of this study is to show this influence. Undoubtedly, the author of The Poem of Yusuf created a touching image of the protagonist, which was appreciated by the Moriscos. The beginning of the poem was borrowed by the author from another aljamiado poem. Despite the persecution of the Spanish Inquisition, the poem has survived in several copies. Together, they represent a combination of traditions of Islamic, pre-Islamic and Christian versification. The article also contains the text of the lament at the grave in the original (Arabic) script and its scientific transcription by V. Menendez Pidal. It also includes a modern Spanish translation made by G. Ticknor. Thanks to his publication, the poem became known as a unique example of “amalgam elements of Eastern and Western civilizations, which were later reflected in Spanish poetry.”