A while back I read an article by Lorne Zelyck, "Matthew 18,1-14 and the Exposure and Sexual Abuse of Children in the Roman World,"Biblica 98.1 (2017): 37-54.
Normally the "little ones" in Matt 18:1-14 are taken to refer to new disciples, who should not be lead astray by mature believers. However, Zelyck argues that:
The context of Matt 18,1-14 suggests …