Sanskrit
अश्रद्धया हुतं दत्तं तपस्तप्तं कृतं च यत् । असदित्युच्यते पार्थ न च तत्प्रेत्य नो इह ॥
aśraddhayā hutaṃ dattaṃ tapas taptaṃ kṛtaṃ ca yat asad ity ucyate pārtha na ca tat pretya no iha
Translation
Whatsoever is wrought without faith, oblation, gift, austerity, or other deed, "Asat" it is called, O Pârtha; it is nought, here or hereafter.
Annie Besant · The Bhagavad-Gita, translated by Annie Besant (4th ed., 1922) — Wikisource · Public Domain
Explanation
The closing verse rings back to Arjuna’s opening question, and in doing so quietly answers it by changing the terms of the inquiry. Arjuna asked what happens to those who sacrifice with faith but no scriptural warrant; twenty-seven verses later, Krishna’s real answer is that scriptural correctness was never the deciding axis at all — śraddhā is. Its total absence renders any act “Asat,” void, whatever else was done correctly, which is the sharpest possible statement of the principle this whole chapter has been building toward one guna-graded category at a time.