Compare Matthew 5:48 and Didache 6:2

“... A potentially more significant parallel might be provided by Did. 6. 2 and Matt. 5. 48. There is widespread agreement that in Matt. 5. 48 // Luke 6. 36, Luke’s reference to being ‘merciful’ is more original, and that Matthew’s ‘perfect’ is due to MattR. Further, this verse in Matthew clearly ties in very closely with a prominent theme in Matthew’s gospel as a whole: namely, the importance of obeying the ethical demands laid upon one with absolute seriousness. The Didachist’s similar interest in the notion of being ‘perfect’ might then relate to what appears to be a significant element of MattR. One may also note the presence of the same word  ºØ in Did. 1. 4. The evidence could then be interpreted as due to two redactors independently developing the idea of ethical ‘perfection’; or it could indicate the Didachist’s dependence on a significant element of MattR, thus showing the dependence of the Didache on Matthew (whether direct or indirect). We may also note the language here of the ‘yoke’ (of the Lord). This is not dissimilar to the reference of the Matthean Jesus to ‘his’ ‘yoke’ in Matt. 11. 28, a verse which many have thought again to resonate with significant Matthean themes, and hence could be due to MattR. In sum, the evidence of this small verse would seem to indicate a close link between the Didache and Matthew’s gospel in particular. ...”