Verse 17.28

अश्रद्धया हुतं दत्तं तपस्तप्तं कृतं च यत्।असदित्युच्यते पार्थ न च तत्प्रेत्य नो इह।।17.28।।

aśhraddhayā hutaṁ dattaṁ tapas taptaṁ kṛitaṁ cha yat asad ity uchyate pārtha na cha tat pretya no iha

Meaning

Whatever you sacrifice, give, or do, and whatever austerities you practice without actually believing in it? It's called 'Asat,' Arjuna. It's useless, both now and in the afterlife. No cap.

Commentary

Bro, like, any sacrifices, gifts, or, like, *major* austerities you do without actually believing in the hype? Yeah, that's totally "Asat." It's, like, a total waste of time, both now and later. No cap.