Natyashastra
छिन्नायां तु चतुर्भागे प्रयोक्तुर्नाश उच्यते । हस्तात्प्रभ्रष्टया वापि कश्चित्वपचयो भवेत् ॥ ३०॥
If the thread is cut into four parts, it is considered a loss for the practitioner. If the thread falls from the hand, it is considered a defect or inauspicious.
english translation
chinnAyAM tu caturbhAge prayokturnAza ucyate । hastAtprabhraSTayA vApi kazcitvapacayo bhavet ॥ 30॥
hk transliteration by Sanscript