When the Children of Israel left Egypt, they did not expect to be in the wilderness for 40 years. (Indeed, 38 years were added to their journey because the generation that left Egypt proved themselves unworthy of entering the Holy Land.)
Jewish law requires every parent to provide their child with the basic necessities: nourishment, shelter and clothing. For food, God provided the Israelites with manna. For water, they had the well that followed Miriam. For shelter, they had the ananei hakavod, the clouds of glory.
What about clothing? In the Book of Deuteronomy, Moses twice notes that the clothing and shoes of the Israelites remained in tact for all 40 years. In Deuteronomy 8:4, Moses recounts: “Your clothing did not wear out upon you, nor did your foot swell these forty years.” In Deuteronomy 29:4, Moses says “And I have led you forty years in the wilderness; your clothes have not worn out upon you, and your shoe has not worn out upon your foot.”
To explain this miraculous occurrence, the Midrash Rabbah records a conversation between Rabbi Eleazer (the son of Rabbi Simeon ben Yochai) and Rabbi Simeon ben Jose, his father in law. In this conversation, Rabbi Simeon explains that the clothes of the Israelites were presented to them by the ministering angels, and that, like the shells of snails, the clothing grew with the Israelites and were cleaned by the clouds of glory. Rabbi Eleazer even asked if the clothes smelled from the people’s perspiration, to which Rabbi Simeon responded that the sweet-scented grass around Miriam’s well constantly freshened the smell of the clothing (Deuteronomy Rabbah 7:11).
What the Israelites wore in the wilderness may seem like a trivial detail to describe, but it demonstrates the loving-kindness of God, the Ultimate Provider.