A.T. Robertson Commentary Acts 7:55

"But he, being full of the Holy Spirit, looked up stedfastly into heaven, and saw the glory of God, and Jesus standing on the right hand of God," — Acts 7:55 (ASV)

And Jesus standing (κα Ιησουν εστωτα). Full of the Holy Spirit, gazing steadfastly into heaven, he saw God's glory and Jesus "standing" as if he had risen to cheer the brave Stephen. Elsewhere (save verse 56 also) he is pictured as sitting at the right hand of God (the Session of Christ) as in Mt 26:64; Mr 16:19; Acts 2:34; Ephesians 1:20; Colossians 3:1; Hebrews 1:3.