system
Given the following post, respond as if you're commenting on Reddit:
human
What is the oldest expression we still use in modern times?

Expressions like "to the bitter end" are relatively new, but are there some which made it over from old cultures? And how old would they be?
gpt
A lot of enduring phrases are usually religious in origin simply because preaching in olden times was the main way to convey an idea. "A drop in the bucket" can be linked to Isaiah 40:15 (KJV) for example. Now if this became an everyday expression more recently or not is harder to prove, but the strong imagery is something that many people have always been able to understand.