The first stage gathers several referents, and the second presents attributes, functions, consequences, or claims belonging to them. The speaker ordinarily does not reintroduce the proper name of each referent beside its predicate.
For example, “night and day; repose and seeking livelihood” gives two items and two associated purposes. Context and experience link repose to night and earning a livelihood to day. This recoverable matching is what organizes the figure.
One could explicitly say, “Night is for rest; day is for work.” That is clear prose, but it removes the audience's small act of matching which gives laff wa nashr its characteristic effect.