Sayyiduna Abdullah bin Mughaffal (may Allah be pleased with him) narrates: The Prophet (peace and blessings be upon him) said: "The believer's lower garment is to the middle of the shin; there is no blame on him for what is between there and the ankles, but whatever is below that will be in the Fire."
Al-Tabarani recorded it. Its chain contains al-Hakam bin Abd al-Malik al-Qurashi, who is da'if (weak).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب اللباس / 8539