Vincent's NT Word Studies
22. Approved (apodedeigmenon). The verb means to point out or shew forth. Shewn to be that which he claimed to be.Miracles (dunamesi). Better, Rev., mighty works. Lit., powers. See on Matt. xi. 20.
Robertson's NT Word Studies
2:22 {Hear these words} (akousate tous logous toutous). Do it now (aorist tense). With unerring aim Peter has found the solution for the phenomena. He has found the key to God's work on this day in his words through Joel. {as ye yourselves know} (kaqws autoi oidate). Note autoi for emphasis. Peter calls the audience to witness that his statements are true concerning "Jesus the Nazarene." He wrought his miracles by the power of God in the midst of these very people here present.