A borrowed expression can be classified through four questions:
1. Identify the source: Qur'an, Hadith, earlier poetry or only a shared theme.
2. Determine what was taken: a phrase, hemistich, full verse or only a distinctive idea.
3. Examine its use: an expressly attributed quotation or words woven into a new text.
4. Check adjustment and disclosure: preserved wording, limited adaptation or a cue identifying unfamiliar borrowed poetry.
Only then apply the rhetorical label. This is more reliable than identifying a device from one isolated word.