John Gill Commentary Acts 6:10

"And they were not able to withstand the wisdom and the Spirit by which he spake." — Acts 6:10 (ASV)

And they were not able to resist the wisdom
In Beza's most ancient copy, and in another manuscript it is added, "which was in him"; that divine wisdom, which the Spirit of wisdom gave him; they were not a match for him with respect to the knowledge of divine things; they could not answer the wise arguments he made use of, fetched out of the Scriptures of truth, in which he was well versed, and had a large knowledge of:

and the Spirit by which he spoke ;
that is, the Holy Spirit, as the above exemplars of Beza, and the Ethiopic version read; the meaning is, they could not resist the Holy Spirit, by which Stephen spoke, so as to overcome him, or put Stephen to silence, or confute him; otherwise they did resist him, or oppose themselves to him, but in vain, and without success; for they always resisted the Holy Ghost in Christ and in his apostles, as their fathers before them resisted him in the prophets, as Stephen observes to them, (Acts 7:51) hereby was fulfilled what our Lord promised to his disciples, (Matthew 10:19Matthew 10:20) (Luke 21:15) .