{And we are witnesses} (kai h(886d)eis martures). Compare "ye
yourselves know" (verse  37 ). Peter thus appeals to what the
audience know and to what the disciples know. He made the same
claim about personal witnesses of the Resurrection of Jesus at
Pentecost ( 2:32 ). Here Peter affirms full knowledge of the work
of Jesus in Judea (for whole country including Galilee and Perea)
and Jerusalem (given mainly in John's Gospel). In the Greek h(936e)
(which) is attracted into the genitive case to agree with the
antecedent pant(936e) (all), a common enough idiom. {Whom also they
slew} (hon kai aneilan). Second aorist active indicative of
anaire(935c) with a as often in Acts ( 2:23  5:30 ). But note
kai (also) in the old MSS., not in the Textus Receptus. They
"also" slew him, went that far, "this crowning atrocity"
(Vincent), kai could here be "even." {Hanging him on a tree}
(kremasantes epi xulou). This same expression used by Peter in
 5:30  which see for discussion.