In plain words
Acts of yajña, giving, and tapas should not be abandoned; they must indeed be performed. Yajña, giving, and tapas are purifying for the wise.
Word for word
The karma of yajña, giving and tapas is not to be abandoned; that is certainly to be done; yajña, giving and tapas indeed are purifiers of the wise.
यज्ञदानतपःकर्म न त्याज्यं कार्यमेव तत्यज्ञो दानं तपश्चैव पावनानि मनीषिणाम्
Other commentaries
The commentators
▸Bhagavadgītābhāṣyam
कः पुनः असौ निश्चयः इति, आह —
यज्ञः दानं तपः इत्येतत् त्रिविधं कर्म न त्याज्यं न त्यक्तव्यम् , कार्यं करणीयम् एव तत् । कस्मात् ? यज्ञः दानं तपश्चैव पावनानि विशुद्धिकराणि मनीषिणां फलानभिसन्धीनाम् इत्येतत् ॥ ५ ॥
In plain words
And what is this certainty? To that he replies —
Sacrifice, giving, austerity — these three kinds of action are not to be dropped, not to be walked away from. They are to be done; do them. Why? Because sacrifice, giving and austerity are purifying — they make you clean through and through — for those with insight, who do not have their eye on the reward. That is what the verse says.
Close to the Sanskrit
"But what is that ascertainment?" — thus (being asked), he says —
Sacrifice, giving, austerity — this threefold action is not to be abandoned, not to be relinquished; it is to be done, indeed it is to be performed. Why? Because sacrifice, giving, and austerity alone are purifying, that is, producers of complete purity, for the thoughtful who do not aim at the fruit. This is what is said.