B.G 2.56
दुःखेष्वनुद्विग्नमनाः सुखेषु विगतस्पृहः। वीतरागभयक्रोधः स्थितधीर्मुनिरुच्यते ॥२-५६॥
duḥkhēṣvanudvignamanāḥ sukhēṣu vigataspr̥haḥ। vītarāgabhayakrōdhaḥ sthitadhīrmunirucyatē ॥2-56॥
He whose mind remains unperturbed in sorrow and devoid of desires for pleasures, who is free from passion, fear, and anger, and who is established in steadfast wisdom is called a 'muni', i.e. sage.
Gīta Bhāshya 2.56
Described characteristics of 'sthitha-prajna' are the very things to be cultivated by spiritual aspirant. Taste, passion, and love are attachments to what is not beneficial.
Same (characteristics of 'sthita-prajna') is clarified further in the next three verses. These are means to knowledge as well. Hence, it is said:
"That very thing which are to be practiced by the inquisitive for perfection are the characteristic of the wise.
-states proverb.
'rāga' i.e. passion is being attached to what is not beneficial.
"Taste, passion, and love are said to be attachments to what is not beneficial."
-states word encyclopedia.