How did the Quran and Hadith Found their Way into Persian Poetry?

Iranians who had experienced the Sassanid class system embraced Islam very quickly because of their interest in Islamic justice; and after learning Arabic language, they were strongly influenced by the Quran and hadith. Lexical items from the Quran, hadith, and Islamic teachings, Quranic hints, and allusions to prophets’ life stories began to impact Persian poetry from 3rd century onward. From 4th century onward, the hadiths and features of the Islamic characters were reflected in Persian poetry too. The minor lexical impact gradually changed into extensive concept formation and deep, spiritual influence. This trend reached a point where in the 5th century some Persian poets were using their poetry to preach, instruct, and offer gnostic and ethical teachings.