Bhagavad-gītā 17.13
BG 17.13
Open the full passageविधिहीनमसृष्टान्नं मन्त्रहीनमदक्षिणम् । श्रद्धाविरहितं यज्ञं तामसं परिचक्षते ॥१३॥
Sanskrit
vidhi-hīnam asṛṣṭānnaṁ mantra-hīnam adakṣiṇam śraddhā-virahitaṁ yajñaṁ tāmasaṁ paricakṣate
Translation
Any sacrifice performed without regard for the directions of scripture, without distribution of prasādam [spiritual food], without chanting of Vedic hymns and remunerations to the priests, and without faith is considered to be in the mode of ignorance.