What supports an ījāz al-qaṣr reading of “ḥifẓu al-kitābi ḥifẓun lil-maʿrifa”?

Supplementary Practice 11: Report, Objection-Reply and Instruction

• Every genitive complement has been deleted
• A broad implication in few words without a required deletion
• A conditional clause must be omitted
• It only locates an action in time