असूर्या नाम ते लोका अन्धेन तमसावृताः।
तांस्ते प्रेत्याभिगच्छन्ति ये के चात्महनो जनाः॥
asuryā nāma te lokā andhena tamasāvṛtāḥ
tāṁste pretyābhigacchanti ye ke cātmahano janāḥ
Devilish (asurya) are those worlds called, with blind darkness (tamas) covered o’er! Unto them, on deceasing, go whatever folk are slayers of the Self. -Isha Upanishad verse 3
Isa Upanishad is one of the principal Upanishads and it is part of the Yajurveda. In fact, Isha Upanishad is the last chapter (chapter 40th) of White Yajurveda Samhita.
It says that after death, people who do not believe in the self go to a devilish world where darkness prevails forever. Buddhists do not accept the presence of the Atman or self. So according to the Vedas, the same fate is awaiting for them.
Also, we found the same opinion in Manusmriti.
All those traditions (smriti) and those despicable systems of philosophy, which are not based on the Veda, produce no reward after death; for they are declared to be founded on Darkness. -Manusmriti 12.95
Reference -
- Upanishads
- Manusmriti translated by George Buhler