«وأما العقد فهو أن ينظم نثرا لا على طريق الاقتباس»
ʿAqd is the versification of prose, rather than the direct incorporation used in iqtibās.
ʿAqd takes the content of an earlier prose expression and casts it into measured verse. It is not merely inserting prose wording unchanged: the original meaning receives poetic metre, arrangement and rhythm.
A sound example preserves the central sense while producing effective verse. If the point of the earlier saying disappears, the relation to the prose source becomes weak.