Is it permissible to pray for eloquence in poetry to become learned and skilled, or is that a sin because poetry is the speech of Satan?

A Muslim is permitted to supplicate for whatever permissible things they wish, even during prayer, based on the Prophet's (peace be upon him) saying: "Then he should choose the supplication most pleasing to him and supplicate."

Poetry is a form of speech: its good parts are good, and its bad parts are bad. The good parts are taken, and the bad parts are left, based on the Prophet's (peace be upon him) saying: "Poetry is like speech: its good is like the good of speech, and its bad is like the bad of speech."

The Companions and scholars permitted poetry due to the need for it in understanding the Arabic language, quoting it in exegesis, knowing the meanings of Allah's and His Messenger's words, and using it as evidence for genealogy, history, and the days of the Arabs.

Therefore, it is permissible to supplicate for skill in poetry and to use it as a means to clarify the truth, spread virtues, and support Islam.