Drinking wine, killing a Brahmana, and the violation of the preceptor's bed, are sins when committed consciously, can never be expiated. The only expiation laid down for them is death.
सुरापानं ब्रह्महत्या गुरुतल्पमथापि वा। अनिर्देश्यानि मन्यन्ते प्राणान्तमिति धारणा॥