The meaning of “discarding what is bad” is INCLUDED in vipassana, Lang.
Vipassana is defined as follows in the section, “2.3.3.32. Samathavipassanāduka” at, “2.3.3. Suttantikadukanikkhepa of dhammasaṅgaṇī“:
“Tattha katamā vipassanā? Yā paññā pajānanā … pe … amoho dhammavicayo sammādiṭṭhi—ayaṃ vuccati vipassanā.”
Therefore, vipassana is connected to paññā (wisdom), dhammavicaya sabbojjhanga, and sammā diṭṭhi.
– It is the ability “to see” things as they really are. “Passa” also means “to see.”
– With that understanding, one would know what to “discard” and what to “take in.”