The Hebrew noun שׁלג (sheleg) means "snow." One use of שׁלג (sheleg) is to describe the weather phenomenon of snow, as in 1 Samuel 23:20: "He also went down and killed a lion in a pit on a day when snow (השׁלג) had fallen." Given its white appearance, snow is often poetically connected with the idea of purity. For example, Isaiah 1:18 draws on the poetic purity of snow, paralleled in this passage with wool, to describe the cleansing of sin: "Come now, let us argue it out, says the LORD: though your sins are like scarlet, they shall be like snow; though they are red like crimson, they shall become like wool." The white appearance of snow is also used negatively to describe the appearance of leprosy, and the change leprosy produces on the skin. For example, Numbers 12:20 describes Miriam's leprosy as follows: "When the cloud went away from over the tent, Miriam had become leprous, as white as snow (כשׁלג)."