Dakshasmriti 5.2

5.2

śauce yatnaḥ sadākāryyaḥ śaucamūlodvijaḥ smṛtaḥ
śaucācāravihīnasya samastaniṣphalāḥ kriyāḥ

Effort should always be made toward purification; the twice-born is said to have purification as his root. / For one devoid of purification and proper conduct, all rituals are fruitless.