Analysis:

This quatrain by Saadi Shirazi is a reflection on the transient nature of human relationships and the inevitability of change. Let's break down each line:

Line 1: گر زحمت مردمان این کوی از ماست

"If the trouble of the people of this neighborhood is because of us"
The speaker is considering the possibility that they are the cause of some disturbance or discomfort for the people around them.

Line 2: یا جرم ترش بودن آن روی از ماست

"Or the fault of that sour face is ours"
The speaker is contemplating whether their actions have caused someone to treat them with disdain or hostility.

Line 3: فردا متغیر شود آن روی چو شیر

"Tomorrow that face will change like a lion"
The speaker predicts that the person who is currently treating them poorly will eventually change their behavior, perhaps becoming even more aggressive.

Line 4: ما نیز برون شویم چون موی از ماست

"And we too will leave like hair from dough"
The speaker anticipates leaving this situation, comparing themselves to hair that can easily be removed from dough. This suggests a sense of detachment and resignation.

Themes explored in the quatrain:

Transience of relationships: The speaker acknowledges that relationships can change quickly and unexpectedly.
Inevitability of change: The speaker recognizes that change is a constant in life and that people and situations are always in flux.
Detachment: The speaker seems to have a detached perspective on the situation, suggesting that they are not overly invested in the outcome.

This quatrain is a meditation on the impermanence of human connections and the importance of maintaining a sense of detachment in the face of adversity. The speaker seems to be resigned to the fact that people and situations change over time, and that it is best to accept this reality rather than become overly attached to any particular outcome.