What do you mean when you meet an old friend in another country and there is dust on your clothes?

This sentence expresses the meaning that former familiar friends meet in a strange place, and both of them are in a difficult environment

"Foreign land" refers to a strange place, while "meeting an old friend in a foreign land" refers to meeting someone you once knew. "Dust on clothes" symbolizes the hard life of two people, as well as the fatigue and hardship brought by various difficulties and challenges. Their clothes are polluted by wind and dust, which also reflects the hardships and difficulties of their hard work outside.

This sentence conveys a feeling of mutual understanding by depicting the images of two people. It reminds people that meeting familiar friends in a strange environment can bring comfort and support, and also makes people realize that it is not easy to work hard outside, and it needs persistence and hard work.