וַיֵּ֥שְׁתְּ מִן־הַיַּ֖יִן וַיִּשְׁכָּ֑ר וַיִּתְגַּ֖ל בְּת֥וֹךְ אָהֳלֹֽה׃
And he drank of the wine, and was drunken; and he was uncovered within his tent.
Rashi on Genesis
ויתגל AND HE UNCOVERED HIMSELF — This is the Hithpael form.
Radak on Genesis
וישת מן היין וישכר, he drank without setting himself a limit until in the end he became drunk and disgraced himself.
Haamek Davar on Genesis
Within his tent - the expression should have been "in his tent"; "within" means in the middle of, just as "within the garden" (Gen. 2:9) and in a few other places. And it is not typical to put one's place of sleeping in the middle of the tent, rather, to one side. And this appears to have been a cause for the deed of his younger son, who "played" with him as he was asleep due to his drunkenness. This is beside the known drash [ed. note: castration].