Interpretation of the whole poem: you often ask me when I will come home, and I don't have a fixed time to come back; It is raining heavily in autumn night in Bashu area, and the pond is full of water. When you and I can be together again,
Talking with you at the west window to cut the candle at night; What if it rains tonight?
What you mean by this sentence is: a conversation by candlelight in the west window.