A.T. Robertson Commentary Acts 26:13

"at midday, O king, I saw on the way a light from heaven, above the brightness of the sun, shining round about me and them that journeyed with me." — Acts 26:13 (ASV)

At midday (ημερας μεσης). Genitive of time and idiomatic use of μεσος, in the middle of the day, more vivid than μεσημβριαν (22:6).

Above the brightness of the sun (υπερ την λαμπροτητα του ηλιου). Here alone not in Ac 9; 22, though implied in 9:3; 22:6, "indicating the supernatural character of the light" (Knowling). Luke makes no effort to harmonize the exact phrases here with those in the other accounts and Paul here (verse 16) blends together what Jesus said to him directly and the message of Jesus through Ananias (9:15). The word λαμπροτης, old word, is here alone in the N.T.

Shining round about me (περιλαμψαν με). First aorist active participle of περιλαμπω, common Koine verb, in N.T. only here and Lu 2:9.