Atharvavedaparishishta 26.4.2

26.4.2

vidveṣe kaṭutailāktā dvidalā tu ṣaḍaṅgulā | sarvato granthihīnā tu viprāṇāṃ syāt samic chubhā ||

In [a rite of] sowing dissension, a split [stick] of six finger-breadths is smeared with pungent mustard oil. / For Brahmins, an auspicious sacrificial stick should be entirely free of knots.