Kaushitakagrihyasutra 2.1.29

2.1.29

iyaṃ duruktaṃ paribādhamānā varṇaṃ pavitraṃ punatī na āgāt prāṇāpānābhyāṃ balamāviśantī sakhā devī subhagā mekhaleyam iti trirmekhalāṃ parivṛtya trivṛtātrivṛtenaikagranthirekaḥ \29\

With: 'Fending off harsh speech, purifying the caste, a purifier, she has come to us, entering strength through in-breath and out-breath, a friendly goddess, auspicious is this girdle,' having wound the girdle three times, threefold or three times tripled, there is a single knot;