tainted money spent for pious deeds will not give benefit

अधर्मोपार्जितैर्योऽर्थैः यो करोत्योर्ध्वदैहिकम्।

न स तस्य फलं प्रेत्य भुङ्तेऽर्थस्य दुरागमात्॥

इन्दिश्चे स्प्रूचे ३४३८ महाभारते

adharmopārjitairyo'rthaiḥ yo karotyordhvadaihikam|

na sa tasya phalaṁ pretya bhuṅte'rthasya durāgamāt||

indiśce sprūce 3438 mahābhārate

If a person is undertaking pious activities for eternal benefits during and after death, and if the money spent for such activity comes from sources which are tainted, he would not enjoy the fruit of it, because the money that has come into his hands in a bad way and  for that reason he would never be able to enjoy the fruits of such deeds either in this world or in the next world. 

The tainted nature of the wealth earned would vitiate the purity of such action.

k v ananthanarayanan

यः whoever अधर्म unrighteous means उपार्जितैःearned अर्थैः through money, wealth ऊर्ध्व दैहिकं rites expecting for benfefits in the future life tooकरोति does तस्य his प्रेत्यः benefits after departure from this worl अर्थस्य of the wealthदुरागमात् wrong source फलं effects न भुङ्ते does not enjoy