Nearly all modern scholars interpret σήμερον in Luke 23:43 as modifying ἔσ. ("today you will be with me in paradise"). The alternative, that σήμερον modifies λέγω ("Truly I say to you today"), is usually dismissed, if mentioned at all. This study argues that the latter reading has prima facie plausibility, since it can be understood—in line with a widely accepted eschatologisation of "today" in Luke (cf. 4:21; 19:9)—as emphasising the immediacy of Jesus' response in contrast to the temporal vagueness of the penitent thief's request ("Remember me when …"). A thorough investigation of this issue is undertaken, using both a survey of patristic evidence and a methodologically innovative statistical analysis of syntactic patterns in Luke-Acts. The evidence indicates that the conventional paradise-today reading is more likely, albeit not certain; translations and commentaries should at least alert readers to the alternative. The meaning of σήμερον under the paradise-today reading is briefly discussed, arguing that despite a probable eschatological connotation, the literal chronological sense should be retained. Accordingly, the saying is best understood as a pronouncement of clemency with immediate results: the penitent thief is to enter paradise with Jesus that very day.