IshNum 90:9 :ܗ݀ܝ ܕܟܣܝܬ ܥܢܢܐ܂ ܩܛܪܝܐ܃ ܕܠܘ ܠܡ ܗ݀ܝ ܡܛܪܢܝܬܐ܂ ܥܠ ܕܗ݀ܝ ܩܫܝܐ ܐܝܟ ܟܐܦܐ‏ : as for "the cloud covered" (Numbers 9:15): the Qatarite says it is not a rain cloud, because it is as hard as stone
See the entire entry for meṭrān(āy) adj. rainy