Question arises - while the ritual is performed by the priest, he chants the mantras, he performs the pooja etc., how the result can go to the yajamana or performer ?
Jaimini sutra says
शास्त्रफलं प्रयोक्तरि - meaning result is with the performer(yajamana) or one who gets the ritual conducted by spending for it.
क्रियाकर्तुराचार्यस्य दक्षिणया क्रीतत्वात (halant) तदतिरिक्तफलसंबन्धानुपपत्तेः फलभाक्त्व यजमानस्यैव
The yajamana (performer) is buying/hiring the acharya or priest with the dakshina. At that point of time other than this ,no relationship exists between the priest and a third person. The priest is completely bought out by the yajamana at the time of the ritual. Hence the result goes entirely to the yajamana. Once again the importance of dakshina can be seen. In the absence of proper dakshina this transfer of the result to the yajamana does not take place properly.