Dakshasmriti 2.20

2.20

yadanyatkurute karma na tasya phalamaśnute
sandhyākarmāvasāne tu svayaṃ homo vidhīyate
svayaṃ home phalaṃ yattu tadanyena na jāyate

Whatever other rite he performs, he does not enjoy its fruit. / At the conclusion of the twilight devotion rite, offering into the fire is prescribed to be done by oneself; / the fruit that comes from making the fire offering oneself does not arise through another.