Why did God forbid pilgrims from wearing sewn garments, and what is the wisdom behind that?

Allah has enjoined Hajj upon the one who can afford it, once in a lifetime, making it a pillar of Islam. The legitimacy of disrobing from sewn garments during Hajj and 'Umrah (definition) carries many wisdoms. Among them are: remembering the state of people on the Day of Resurrection (barefoot and unclothed), humbling the soul and purifying it from arrogance, instilling in it the principle of closeness, equality, and austerity, shunning extravagance, and empathizing with the poor and needy. "Sewn garment" refers to that which is tailored to the limbs of the body, and not simply what contains threads.