You mentioned Eusebius, he quotes 29 times in his writings Matthew 28:19 and most often in Eusebius the quote has this form: "Πορευθέντες μαθητεύσατε πάντα τὰ ἔθνη ἐν τῷ ὀνόματί μου" - Go and teach all the nations in My Name (PG t. 20, c. 221, c. 1425, PG t. 22, c. 233, c. 240, c. 241, c. 692...