Chapter 17 · The Three Kinds of Faith · Krishna said
Bhagavad Gita 17.11 — Sattvic sacrifice
अफलाङ्क्षिभिर्यज्ञो विधिदृष्टो य इज्यते। यष्टव्यमेवेति मनः समाधाय स सात्त्विकः ॥
aphalāṅkṣibhiryajño vidhidṛṣṭo ya ijyate | yaṣṭavyameveti manaḥ samādhāya sa sāttvikaḥ ||
Meaning
A sacrifice done according to scripture, without wanting reward, with the firm feeling 'this is my duty', is sattvic.