Luke indicates his views about Jesus in a speech attributed to Peter on the day of Pentecost – the first point at which Luke reports preaching about Jesus after his exaltation. In addition to the image of Jesus baptizing in the Spirit (which Lk 3:16 presumably derives from “Q”), in Acts 2:33 Jesus “pours out” the Spirit, a clear allusion to God pouring out the Spirit in 2:17-18 (the only other passage in Luke-Acts that uses ekcheo). Jewish texts also speak of God pouring out wisdom (Sir 1:9) as his gift (Sir 1:10; cf. Acts 2:38). But the most obvious source of the language, in view of the allusion to Acts 2:17-18, is Joel 2:28-29, where God pours out the Spirit.
Moreover, Peter interprets the name of the “Lord” (the divine name in Hebrew) in terms of Jesus of Nazareth in Acts 2:21, 38 (interpreting Joel 2:32 by way of Ps 110:1). By concluding that the gift of the Spirit was available to “as many as God would call,” Luke clearly echoes the end of Joel 2:32 (3:5 LXX), completing the quotation interrupted in Acts 2:21. That is, having finished his exposition of “whoever calls on the Lord’s name” (2:21) by showing that the name on which they must call is Jesus’ (2:38), he concludes the quotation in 2:39. The salvific name of God, then, is “Jesus.” That other early Christians interpreted the Joel text similarly in the 50s (Joel 2:32 in Rom 10:9, 13) signals that Luke follows an earlier tradition of interpretation.
Craig S. Keener, The Historical Jesus of the Gospels (Grand Rapids, MI: William B Eerdmans Publishing Company, 2009), 279.