Musannaf Ibn Abi Shayba 16:562

Abu Bakr narrated to us, he said: Isma'il bin Ibrahim narrated to us, from Ayyub, from Abu Yazid al-Muzani, who said: Umar used to forbid women from wearing Qibati (a type of thin, white Egyptian linen). They said: "It does not reveal (the skin)." He said: "Even if it does not reveal, it describes (the shape of the body)."