Wherefore he saith (dio legei). Apparently a free adaptation of Isa 26:19; Isa 60:1. The form anasta for anastēthi (second person singular imperative second aorist active of anistēmi) occurs in Act 12:7.
Shall shine (epiphausei). Future active of epiphauskō, a form occurring in Job (Job 25:5; Job 31:26), a variation of epiphōskō. The last line suggests the possibility that we have here the fragment of an early Christian hymn like 1Ti 3:16.