Iqtibās brings wording from the Qurʾān or hadith into a new prose or poetic composition as part of that composition; taḍmīn incorporates another poet’s line or part of one; ilmām borrows an idea without that textual inclusion. Source and method of incorporation are decisive.
DeviceSourceTreatment
IqtibāsQurʾān or hadithLiterary insertion of wording
TaḍmīnAnother poet’s verseIncorporation of poetic wording
IlmāmMeaning in earlier literatureNew expression of an idea
Explicitly citing a Qurʾānic passage as scripture should be distinguished from the literary mode of iqtibās.