وَإِنْ لَمْ يَكُنْ لَهُ نِجَادٌ وَلَا كَلْبٌ وَلَا فَصِيلٌ
Even if he has no sword strap, dog, or camel calf.
These cases illustrate that an allusion does not require the described physical object to exist in every instance. A known tall or generous person may still be described by a conventional expression associated with those qualities.
Two aspects must be kept distinct: permissibility of a literal reading and the actual presence of the literal circumstance. Non-exclusion of the literal meaning does not require that circumstance to obtain on each occasion.