«وَبِالْوَالِدَيْنِ إِحْسَانًا»
And show kindness to your parents.
Iḥsānan is an accusative verbal noun; a suppressed governing verb, functionally akin to aḥsinū, can account for its directive sense. It therefore belongs to the practical domain of obligation despite lacking an explicit imperative verb.
The covenant thus unites worship, filial conduct, and speech as coordinated duties. Both expressed form and recoverable sense matter.