B.G 9.27 and 28
यत्करोषि यदश्नासि यज्जुहोषि ददासि यत्। यत्तपस्यसि कौन्तेय तत् कुरुष्व मदर्पणम् ॥२७॥
Whatever you do, whatever you eat, whatever you offer in sacrifice and give, whatever austerity you perform, O son of Kunti, do that as an offering to Me.
शुभाशुभफलैरेवं मोक्ष्यसे कर्मबन्धनैः। संन्यासयोगयुक्तात्मा विमुक्तो मामुपैष्यसि ॥२८॥
Thus, you will be freed from the results of both good and bad actions, and the bondage of karma. With yourself engaged in the path of renunciation and Yoga, you will be liberated and reach Me.
Gīta Bhāshya 9.27 and 28
As devotion to the Lord is the underlying primary principle - 'Whatever you do, do that as an offering to the Lord'
अतो यत्करोषि ॥२७, २८॥
Therefore, (as devotion is the core principle as explained), it is clarified by the verse 'yatkaroṣi', i.e. whatever you do, do that as an offering to Me.