Bhagavad Gita Chapter 18 Verse 5
यज्ञदानतपःकर्म, न, त्याज्यम्, कार्यम्, एव, तत्,
यज्ञः, दानम्, तपः, च, एव, पावनानि, मनीषिणाम्।।5।।
YagyadaantapHkarm, na, tyaajyam’, kaaryam’, ev, tat’,
YagyaH, daanm’, tapH, ch, ev, paavnaani, maneeshinaam’ ||5||
Translation: (YagyadaantapHkarm) the acts of yagya, charity and austerity (na, tyaajyam’) should not be relinquished, rather (tat’) they (ev) must / definitely (kaaryam’) be performed because (yagyaH) yagya (daanm’) charity (ch) and (tapH) austerity (ev) acts only (maneeshinaam’) wise men (paavnaani) are the purifiers. (5)
Translation: The acts of yagya, charity and austerity should not be relinquished; rather, they must be performed because the acts of yagya, charity and austerity only are the purifiers of the wise men.
Important: Here, the meditation (tap) done by hathyog is not mentioned; here, there is mention of the austerity (tap) described in Gita Chapter 17 Verse 14 to 17.