यज्ञप्रयोग-s are the traditional technical methods to achieve desires. It is therefore important to get the details correctly; just as an incorrectly operated machine can injure the worker in a factory, a यज्ञ undertaken without attention to detail can backfire. The फलसमर्पण to भगवान् at the end of a यज्ञ can take care of unintentional mistakes, but wanton carelessness will hurt.
For those quoting:
मूर्खो वदति विष्णाय विद्वान् वदति विष्णवे । उभयोः सदृशं पुण्यं भावग्राही जनार्दनः ||, the better method might be to tryभक्ति-oriented methods such as the many powerful स्तोत्र-s that are there in the संप्रदाय.
So what happens when we don't take care in a यज्ञ? बोधायन गर्ह्यसूत्र (प्रथमप्रश्ने अष्टमोध्यायः, at the end) says:
(alternate reading for स्वर is स्वाहा; online link)
In a way, the above also lays out responsibilities: e.g. ऋत्विज-s should get the मन्त्र-s perfectly else it impacts them (not the यजमान). But then, since wrong svaras impact the पत्नी, it is your responsibility to select the right ऋत्विज-s. The यजमान-s should ensure that आज्य, अन्न, and दक्षिण are in good amounts. अग्नि is a joint responsibility. If you've been invited to a यज्ञ to be part of the सदस् but you know all of the above are going to be wrong, don't go!
For those quoting:
मूर्खो वदति विष्णाय विद्वान् वदति विष्णवे । उभयोः सदृशं पुण्यं भावग्राही जनार्दनः ||, the better method might be to tryभक्ति-oriented methods such as the many powerful स्तोत्र-s that are there in the संप्रदाय.
So what happens when we don't take care in a यज्ञ? बोधायन गर्ह्यसूत्र (प्रथमप्रश्ने अष्टमोध्यायः, at the end) says:
(alternate reading for स्वर is स्वाहा; online link)
In a way, the above also lays out responsibilities: e.g. ऋत्विज-s should get the मन्त्र-s perfectly else it impacts them (not the यजमान). But then, since wrong svaras impact the पत्नी, it is your responsibility to select the right ऋत्विज-s. The यजमान-s should ensure that आज्य, अन्न, and दक्षिण are in good amounts. अग्नि is a joint responsibility. If you've been invited to a यज्ञ to be part of the सदस् but you know all of the above are going to be wrong, don't go!