Where in the Noble Qur'an was "rain that astonished the disbelievers" mentioned, and what is the interpretation of this verse?

The verse 20 from Surat Al-Hadid: "Know that the life of this world is only play and amusement, pomp and mutual boasting among you, and rivalry in respect of wealth and children. It is like the rain whose vegetation is pleasing to the disbelievers; then it dries up and you see it turning yellow; then it becomes scattered pieces. And in the Hereafter there is severe punishment and forgiveness from Allah and [His] approval. And what is the life of this world except the enjoyment of delusion" means that the life of this world is like vegetation whose greenness and freshness delight people, then it dries up, withers, and breaks into pieces. It has been said that "the disbelievers" here refers to farmers who are pleased with the plants grown by the rain, or to those who disbelieve in Allah and are delighted by the adornments of this world because their admiration for what they see does not extend to recognizing the power of the Creator.