Parallel
Revelation 6:9
Nestle 1904 Greek New Testament · Berean Standard Bible
Καὶ ὅτε ἤνοιξεν τὴν πέμπτην σφραγῖδα εἶδον ὑποκάτω τοῦ θυσιαστηρίου τὰς ψυχὰς τῶν ἐσφαγμένων διὰ τὸν λόγον τοῦ Θεοῦ καὶ διὰ τὴν μαρτυρίαν ἣν εἶχον
And when the Lamb opened the fifth seal, I saw under the altar the souls of those who had been slain for the word of God and for the testimony they had upheld.