मनु स्मृति - श्रेयोऽनुशासनम्

अहिंसयैव भूतानां कार्यं श्रेयोऽनुशासनम् ।
वाक्चैव मधुराश्लक्ष्णा प्रयोज्या धर्ममिच्छता ॥

- मनु स्मृति

When you are training (animals or students), one must not use physical force (or hurt them). They must be won over by nice words and not by a cane.

- Manu Smriti