Bhagavad-gītā As It Is · Text 17.28
Om Tat Sat, spiritual faith and proper intention
अश्रद्धया हुतं दत्तं तपस्तप्तं कृतं च यत् ।
असदित्युच्यते पार्थ न च तत्प्रेत्य नो इह ॥ २८ ॥
aśraddhayā hutaṁ dattaṁ
tapas taptaṁ kṛtaṁ ca yat
asad ity ucyate pārtha
na ca tat pretya no iha
Anything done as sacrifice, charity or penance without faith in the Supreme, O son of Pṛthā, is impermanent. It is called asat and is useless both in this life and the next.
Read Śrīla Prabhupāda's purport on Vedabase.io