What shifts when the famous “aḍāʿūnī” line enters its new poem?

Iqtibās and Taḍmīn: Quoting Scripture and Incorporating Poetry

• The earlier hemistich becomes merely a fortress name
• The borrowed words retain no meaningful relation
• A Qur’anic expression is turned into a Hadith
• The lament about neglect is applied to a new circumstance