Bhagavad Gita 9.27

Whatever you do, whatever you eat, whatever you sacrifice and give, whatever austerities you practice, do all as an offering to Me.

यत्करोषि यदश्नासि यज्जुहोषि ददासि यत्।
यत्तपस्यसि कौन्तेय तत्कुरुष्व मदर्पणम्॥

yatkaroṣi yadaśnāsi yajjuhoṣi dadāsi yat|
yattapasyasi kaunteya tatkuruṣva madarpaṇam||

English translation (above): Shri Purohit Swami (1935), public domain. Sanskrit text via github.com/gita/gita (Unlicense).