Matthew 18:6

But whoever shall occasion the fall of one of these little ones who believe in me, it would be better for him to have a millstone hung round his neck and to be drowned in the depths of the sea.

Mark 9:42

"And whoever shall occasion the fall of one of these little ones who believe, he would be better off if, with a millstone round his neck, he were lying at the bottom of the sea.

Matthew 18:10

"Beware of ever despising one of these little ones, for I tell you that in Heaven their angels have continual access to my Father who is in Heaven.

Matthew 18:14

Just so it is not the will of your Father in Heaven that one of these little ones should be lost.

Luke 17:1-2

Jesus said to His disciples, "It is inevitable that causes of stumbling should come; but alas for him through whom they come!

Acts 9:5

"Who art thou, Lord?" he asked. "I am Jesus, whom you are persecuting," was the reply.

Romans 14:13-15

Therefore let us no longer judge one another; but, instead of that, you should come to this judgement--that we must not put a stumbling-block in our brother's path, nor anything to trip him up.

Romans 14:21

The right course is to forego eating meat or drinking wine or doing anything that tends to your brother's fall.

Romans 15:1-3

As for us who are strong, our duty is to bear with the weaknesses of those who are not strong, and not seek our own pleasure.

1 Corinthians 8:9-13

But take care lest this liberty of yours should prove a hindrance to the progress of weak believers.

1 Corinthians 10:32-33

Do not be causes of stumbling either to Jews or to Gentiles, nor to the Church of God.

2 Thessalonians 1:6-9

A plain token of God's righteous judgement, I say, since it is a righteous thing for Him to requite with affliction those who are now afflicting you;

Treasury of Scripture Knowledge

Summary

But whoso shall offend one of these little ones which believe in me, it were better for him that a millstone were hanged about his neck, and that he were drowned in the depth of the sea.

General references

Bible References

Little

Matthew 18:10
"Beware of ever despising one of these little ones, for I tell you that in Heaven their angels have continual access to my Father who is in Heaven.
Luke 17:2
It would be well for him if, with a millstone round his neck, he were lying at the bottom of the sea, rather than that he should cause even one of these little ones to fall.

General references

2 Corinthians 6:3
We endeavour to give people no cause for stumbling in anything, lest the work we are doing should fall into discredit.
Philippians 2:4
each fixing his attention, not simply on his own interests, but on those of others also.