Recent literature on the use of the Old Testament in Hebrews makes frequent reference to “prosopological exegesis” (PE)—that is, the idea that the author of Hebrews inserts new speakers into old scenes such that, for example, the speaker in Psalm 40:6–8 (LXX 39:7–9), cited in Hebrews 10:5–7, has become Jesus rather than David. The question with which this essay is concerned is how we may not only identify the insertion of a new speaker into an OT text, but also identify when that new speech act took place. Some such instances are straightforward; for example, Heb 10:5 introduces the words of Jesus with “when he enters the world, he says . . .” Others are less easily located, such as the Father’s citation of Ps 2:7 to his Son (Heb 1:5), and in other instances there may not be an answer to the “when?” question at all. This paper first argues that it is appropriate to ask of any given instance of PE the “when?” question, even though it may occasionally turn out to be unanswerable. It then explores one particularly debated instance of PE in Hebrews: Jesus’ citation of Ps 22:22 (LXX 21:23) and Isaiah 8:17–18 in Heb 2:12–13. It concludes that, contra recent scholarship, all three of these citations are spoken by Jesus in the context of his death.