Stephen Carlson wrote:The frequency may be un-Greek, but the phrase itself is, being found in Greek writers (though admittedly not the best).
To split hairs, there is a difference between, "the combination of words" and "the phrase".
A phrase may have more or a further developed meaning than its constituent parts added together would. In this case, if the meaning of πάσας τὰς ἡμέρας in Matthew 28:20 were "continually", "as long as" or "forever", rather than "throughout all the days of" (a simple countable and definable period of time) we might be able to consider it a phrase rather than just a combination of words.
I not proficient in handling statistical data from these searches, but my limited corpus (free subscription) TLG search, yields instances of the phrase "πάσας τὰς ἡμέρας τῆς ζωῆς" (followed by various possessive pronouns) only in Christan writers. As a highly-improper preposition, it could be that πάσας τὰς ἡμέρας in this phrase simply has the force of "throughout", taken from an adverbial usage of the phrase.
The only one to make a variation on the order of the combination of words among the Christian writers was in Eusebius
EUSEBIUS, Commentaria in Psalmos. {2018.034} wrote:μόνοις δὲ τοῖς
μὴ οἵοις τε οὖσι τὸν πάντα χρόνον τῆς αὐτῶν ζωῆς,
καὶ πάσας αὐτῶν τὰς ἡμέρας τῇ τοῦ Θεοῦ λατρείᾳ
καὶ τοῖς τῷ Θεῷ φίλοις ἔργοις σχολάζειν·
Which is part of the commentary, not the quotation of the text.
Again working with the limited corpus search, the dative plural as used in the NA-USB text of Luke 1:53 comes up once:
CHARITON Scr. Erot. De Chaerea et Callirhoe {0554.001} Book 5 chapter 9 section 6 line 4 wrote:καὶ τοῦτο πάσαις ταῖς ἡμέραις ἐπράττετο μετὰ σπουδῆς,
The non-christian authours seem to be freer in their word-order, perhaps fitting the definition of a combination of words, rather than a phrase.