أمْطَرَ (تِ السّمَاءُ) to rain (it rained)

أمْطَرَ (تْهُم السّمَاءُ) to shower with rain (it rained upon them)

أمْطَرَهُ بـِوَابـِلٍ مِنْ to shower with, storm with, pelt with, pepper with, hail on