Either through ignorance and inexperience of the nature and strength of that liquor, or through the infirmity of the flesh, which was tempted by its great and, to him, new pleasantness, and by the refreshment he found in it under the weary labours of his body, and the sad thoughts of his mind, for the desolate condition of the world. He was uncovered, either to relieve himself against the heat of the climate and season, or from his negligence and carelessness; which might easily happen, because men's garments at that time were loose, as they were in the following ages, when breeches were not in common use, and therefore were peculiarly prescribed to the priests, Exodus 28:42 Ezekiel 44:18-19.
Related Commentaries of Genesis 9:21
Genesis 9:21
21 And he drank of the wine, and was drunken; and he was uncovered within his tent.