“Intertextuality” is a theory concerning the relationships between texts that lead to the creation of new texts. Every single text, therefore, can be regarded as an intertextual that has its roots in previous texts while influencing future texts. This theory was first introduced by Julia Kristeva in 1966. The presence of Qur'anic verses and the eloquent words of the Holy Prophet (Peace and Blessings of Allâh be Upon Him) and Imam Ali (Peace be Upon Him) in the poetry of “Mahyar Deilami”, a prominent Arab poet, first of all, demonstrates the influence of Qur'anic concepts and the words of those great humans on him. This inspired us to conduct the present study on the intertextual relationships between Mahyar Deilami's poetry on the one hand and Qur'anic ayahs as well as the Holy Prophet's and the twelve Imams' ahadith, on the other. To this end‚ parts of Mahyar Deihami's poetry were analyzed. The findings indicated that the ayahs‚ proportionate to their themes, were intentionally influenced by the Qur'anic ayahs and the invaluable hadith of the Holy Prophet. The intertextual analysis also revealed that most frequent instances of Qur'anic and narrative intertextuality were partial negation (ijtirar) and symmetric negation (imtisas).