أَلَيْسَ اللَّهُ بِكَافٍ عَبْدَهُ
Is Allah not sufficient for His servant?
Laysa is a defective verb; Allāhu is its subject, bi-kāfin its predicate with an emphatic additional bāʾ, and ʿabdahu is related to the active participle kāfin. The additional bāʾ does not cancel the predicative sense.
Rhetorically the sentence elicits recognition of divine sufficiency. The discussion asks how hamza scopes over the negative wording, making acknowledgment of the positive truth appropriate. It must not be flattened into an assertion that divine sufficiency is denied.