Reconciling two readings does not create an unrestricted personal choice between washing and wiping in every circumstance. Legal application depends on the relevant case.
Ordinary ablution washing and the qualified permission to wipe over footwear must be distinguished. Wiping over khuffs has its own evidences and conditions; these details are not established by a single grammatical case ending alone.
The interpretive method therefore considers the legal setting, conditions, and supporting evidence together.