«إِنِّي مَا قَتَلْتُ ابْنَكَ سَهْوًا وَلَا عَمْدًا»
I did not kill your son, either accidentally or deliberately.
The opposed adverbs accidental and deliberate both fall under the denial of killing. The statement is not merely “I did not intend it”; it rejects the alleged act in either mode.
By naming both alternatives, the oath sounds exhaustive. Yet an exhaustive-sounding denial is still a claim needing assessment; forceful wording cannot itself settle the case.