One of the best ways to go about it is to look at parallel passages in the Gospels and think about how Matthew, Mark, & Luke conceive of the same event and convey their priorities about that event using word order.
This fact that really came to the forefront for me this afternoon as I was digging through examples of enclitic pronouns. And in this case, things are slightly more complicated by the presence of the clitics, which have a far more limited range of placement than other words, but based on claims about clitics I have made in earlier posts, it should be easier for you to recognize what constituent in this clauses is the focal element.
Consider the following texts:
Matthew 26:34 ἔφη αὐτῷ ὁ Ἰησοῦς· ἀμὴν λέγω σοι ὅτι ἐν ταύτῃ τῇ νυκτὶ πρὶν ἀλέκτορα φωνῆσαι τρὶς ἀπαρνήσῃ με.
“Truly I tell you,” Jesus answered, “this very night, before the rooster crows, you will disown me three times.”
Matthew 26:75 καὶ ἐμνήσθη ὁ Πέτρος τοῦ ῥήματος Ἰησοῦ εἰρηκότος ὅτι πρὶν ἀλέκτορα φωνῆσαι τρὶς ἀπαρνήσῃ με·
Then Peter remembered the word Jesus had spoken: “Before the rooster crows, you will disown me three times.” And he went outside and wept bitterly.
Mark 14:30 καὶ λέγει αὐτῷ ὁ Ἰησοῦς· ἀμὴν λέγω σοι ὅτι σὺ σήμερον ταύτῃ τῇ νυκτὶ πρὶν ἢ δὶς ἀλέκτορα φωνῆσαι τρίς με ἀπαρνήσῃ.
“Truly I tell you,” Jesus answered, “today—yes, tonight—before the rooster crows twice you yourself will disown me three times.”
Mark 14:72 καὶ ἀνεμνήσθη ὁ Πέτρος τὸ ῥῆμα ὡς εἶπεν αὐτῷ ὁ Ἰησοῦς ὅτι πρὶν ἀλέκτορα φωνῆσαι δὶς τρίς με ἀπαρνήσῃ·
Then Peter remembered the word Jesus had spoken to him: “Before the rooster crows twice you will disown me three times.”
Luke 22:34 ὁ δὲ εἶπεν· λέγω σοι, Πέτρε, οὐ φωνήσει σήμερον ἀλέκτωρ ἕως τρίς με ἀπαρνήσῃ εἰδέναι.
Jesus answered, “I tell you, Peter, before the rooster crows today, you will deny three times that you know me.”
Luke 22:61 καὶ ὑπεμνήσθη ὁ Πέτρος τοῦ ῥήματος τοῦ κυρίου ὡς εἶπεν αὐτῷ ὅτι πρὶν ἀλέκτορα φωνῆσαι σήμερον ἀπαρνήσῃ με τρίς.
Then Peter remembered the word the Lord had spoken to him: “Before the rooster crows today, you will disown me three times.”
John 13:38 ἀμὴν ἀμὴν λέγω σοι, οὐ μὴ ἀλέκτωρ φωνήσῃ ἕως οὗ ἀρνήσῃ με τρίς.
I tell you the truth, before the rooster crows, you will disown me three times!
So we’ve got three distinct word orders for this little statement:
τρὶς ἀπαρνήσῃ με
τρίς με ἀπαρνήσῃ
ἀπαρνήσῃ/ἀρνήσῃ με τρίς
What makes them tick?
And no, this is not stylistic variation.