Metzger says: "Besides having wide external support the reading τί also has strong internal probabilities in its favor. There is no reason why the familiar ότι, if original, should have been altered to τί, used here to represent the Semitic exclamation מֶ֥ה ("how!" compare Ps 139:17). On the other hand, copyist who did not perceive the underlying Semitism would have been tempted to assimilate τί to the preceding ότι of ver. 13."Matt 7:13-14 wrote:13 Εἰσέλθατε διὰ τῆς στενῆς πύλης· ὅτι πλατεῖα ἡ πύλη καὶ εὐρύχωρος ἡ ὁδὸς ἡ ἀπάγουσα εἰς τὴν ἀπώλειαν, καὶ πολλοί εἰσιν οἱ εἰσερχόμενοι δι’ αὐτῆς· 14 [ὅ]τι στενὴ ἡ πύλη καὶ τεθλιμμένη ἡ ὁδὸς ἡ ἀπάγουσα εἰς τὴν ζωήν, καὶ ὀλίγοι εἰσὶν οἱ εὑρίσκοντες αὐτήν.
The critical apparatus shows the assimilation to ότι very early, and even some printed editions who's editors haven't made the Semitic connection have followed the ότι reading.
My questions are, how did the author of Matthew understand this Semitism? Was he thinking in Aramaic but it came out in Greek? Was this an expression that Greek speaking Jews would have used regularly? Are there any other examples of this usage anywhere else? Is it a lingual blunder or a legitimate use of τί in 1st century bi-lingual Jewish circles?