It would be better for him to be thrown into the sea with a millstone around his neck than to trip up one of these little ones.
In context
1He said to his disciples, “It is impossible that no one should be tripped up, but how terrible for the one through whom it comes. 2It would be better for him to be thrown into the sea with a millstone around his neck than to trip up one of these little ones. 3Watch yourselves. If your brother sins, rebuke him; and if he repents, forgive him. 4Even if he sins against you seven times in one day and seven times turns back to you saying, ‘I repent,’ you are to forgive him.”