Acts 6:10

They were not able to withstand

(ουκ ισχυον αντιστηνα). Imperfect active of ισχυω, to have strength, and ingressive second aorist active (intransitive) infinitive of ανθιστημ. They continued unable (without strength enough) to take a stand against. Stephen knocked them down, Saul included, as fast as they got up. Stephen was like a battery charged and in action.The wisdom and spirit

(τη σοφια κα πνευματ). Dative case. They stood up against Stephen's wisdom and the Holy Spirit "by whom he spoke" (ω ελαλε). Instrumental case and the relative agrees with "Spirit." He kept on speaking so (ελαλε, imperfect active). It was a desperate situation.