«وَلَوْ شِئْتُ أَنْ أَبْكِيَ دَمًا لَبَكَيْتُهُ»
If I wished to weep blood, I would indeed do so.
Here “shiʾtu” (I wished) is followed by “an abkiya daman,” which explicitly identifies the content of the wish. It must not be analyzed exactly like a conditional in which the verb’s complement is wholly unexpressed.
The comparison teaches a basic method: decide whether a complement is present from the actual wording of each sentence, not from a rule mechanically applied to every occurrence of the verb “to wish.”