“Why is your face sad?”
so the king said to me, 'Why is your face sad, though you are not ill? This could only be sadness of the heart.' I was overwhelmed with fear (Nehemiah 2:2 BSB)
What it sounds like today
Nehemiah strangely terrified just because the king noticed he looked down.
The cultural key
Nehemiah's terror at a sympathetic question seems like an overreaction until you know Persian court protocol. To come before the Great King was to enter a presence expected to radiate joy and favor; visible gloom was a breach of etiquette that could be taken as discontent with the king himself, even as an ill omen against him, and displeasing the monarch could cost a courtier his life. (In the same court, Esther risks death merely by approaching unbidden.) So when Artaxerxes notices his cupbearer's downcast face, Nehemiah is 'overwhelmed with fear', not because the king is angry, but because he has accidentally broken a rule that could prove fatal, and the next words out of his mouth will decide everything.
Recovered meaning
Looking sad before the Persian king was a dangerous breach of protocol, readable as disloyalty, so Nehemiah's fear is rational rather than fragile. The whole mission hangs on how the king chooses to read his face.