This is part of my Exegetical Commentary Project, which can be found here.
Acts 1:15-26: these verses are sometimes appealed to as testimony against hope that Judas will be saved from his sins. They might theoretically refer to this, but strictly speaking they only refer to messier details of Judas’ death, and to Peter’s reassurance that Judas’ betrayal (and thus the need to appoint a new apostle) was prophesied and so nothing to panic about.
Peter’s citation of Psalm 69 (and Psalm 109) is more worrisome, although notably David expects God to save those He punishes and imprisons for their sins, for example at 69:33, when those-being-punished-and-imprisoned-for-their-sins means David. See comments on Psalm 69.
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