Ecclesiastes 10:1

Dead flies cause the ointment of the apothecary to send forth a stinking savour: so doth a little folly him that is in reputation for wisdom and honour.

Cross-references

Ecclesiastes 7:1 says a good name is better than ointment; here, dead flies ruin ointment — both use ointment to discuss reputation and its fragility.

Nehemiah 13:26 recalls Solomon's wisdom undone by foreign wives—a clear example of 'a little folly outweighs wisdom'.

In Matthew 5:13, Jesus uses salt losing its taste—small corruption ruins usefulness, parallel to flies spoiling ointment.