Here is the Sanskrit anuvad, Hindi anuvad, and English translation of Shraddhatraya-Vibhaga Yoga Chapter 17, Verse 17.11.
अफलाकाङ्क्षिभिर्यज्ञो विधिदृष्टो य इज्यते । यष्टव्यमेवेति मनः समाधाय स सात्त्विकः ॥ १७.११ ॥
जो शास्त्र विधि से नियत, यज्ञ करना ही कर्तव्य है —- इस प्रकार मन को समाधान करके, फल न चाहने वाले पुरुषों द्वारा किया जाता है, वह सात्विक है |
A pure sacrifice is one where the religious offerings (made to Myself, the Almighty) are made with true love and adoration for Me. They are offerings that are made in accordance with the rules or Holy laws in our religious scriptures, with no expectation of rewards resulting from the performance of these sacrifices, and offerings that are made from the heart and only with the intention that it is one’s duty to perform this religious sacrifice.