جُبْنًا is a verbal noun connected to the root ج ب ن, meaning cowardice.
In the author’s example the expressed verb is قَعَدَ, so the noun does not reinforce that same verb as a typical cognate accusative would.
Under the book’s stated analysis it is mafʿūl lahu: the reason for staying away.
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Al-Mafʿūl Lahu: Expressing the Reason for an Action
جُبْنًا is a verbal noun connected to the root ج ب ن, meaning cowardice.
In the author’s example the expressed verb is قَعَدَ, so the noun does not reinforce that same verb as a typical cognate accusative would.
Under the book’s stated analysis it is mafʿūl lahu: the reason for staying away.