Jeremiah 12:5

If thou hast run with the footmen, and they have wearied thee, then how canst thou contend with horses? and if in the land of peace, wherein thou trustedst, they wearied thee, then how wilt thou do in the swelling of Jordan?

Cross-reference

Jeremiah 38:4–6 Prophetic fulfillment

In Jeremiah 38:4-6, this warning becomes reality—Jeremiah is thrown into a muddy cistern, the 'horses' he couldn't outrun.

Proverbs 24:10 says fainting in adversity reveals small strength — directly paralleling the idea that failing in easy times predicts failure in hard ones.

1 Samuel 23:3 uses the same 'if you can't handle this, how will you handle worse?' logic, mirroring the rhetorical structure here.