Surah Ar Rum Tafseer

And verily, before that -- just before it was sent down upon them -- they were in despair!

The people to whom this rain came were in despair, thinking that it rain would never fall, just before it came to them. When it came to them, it came at the time of greatest need, so it was a tremendous event for them.

What this means is that they were in need of it before it fell, and there had been no rainfall for a long time, so they were waiting for it at the time when it was due, but it did not come to them at that time. The rain was late, and a long time passed. Then the rain came to them suddenly, after they began to despair, and after their land became dry and barren, it was stirred to life, and it swelled and produced every lovely kind of growth.

Allah says