Acts 13:31

Was seen for many days

(ωφθη επ ημερας πλειους). The common verb (first aorist passive indicative of οραω, to see) for the appearance of the Risen Christ, the one used by Paul of his own vision of Christ (1 Corinthians 15:8), which is not reported by Luke here. For more days (than a few), the language means, forty in all (Acts 1:3).Of them that came up with him

(τοις συναναβασιν αυτω). Dative (after ωφθη) articular participle (second aorist active of συναναβαινω) with associative instrumental case (αυτω), the very men who knew him best and who could not be easily deceived about the reality of his resurrection. But this fact rules Paul out on this point, for he had not fellowshipped with Jesus from Galilee to Jerusalem.Who are now his witnesses

(οιτινες νυν εισιν μαρτυρες αυτου). The very point that Peter used to clinch his argument with such powerful effect (Acts 2:32; Acts 3:15).