Bhagavad Gita · Sankhya YogaChapter 2, Shloka 50 (2.50)

Is merit also bondage? The shloka says that one endowed with understanding casts off both — sukrita (merit) and dushkrita (sin). Why merit too? Because merit also bears fruit (heaven, happiness), and fruit in turn becomes the cause of new birth/bondage — "a chain of gold is still a chain". Shankaracharya: merit and sin fall away through purity of mind and the attainment of knowledge. Ramanuja: merit and sin accumulated from beginningless time, endless, the causes of bondage.

"Yogaḥ karmasu kauśalam" — yoga is skill in action. This is one of the Gita's best-known sentences (today the motto of many institutions too). But "kaushal" does not mean only "skill / efficiency":

• Shankaracharya: The skill is this — the even-minded understanding, in success and failure, of one engaged in the actions of his svadharma, with a mind offered to Ishvara — by which even actions that by nature bind give up their binding nature through even-minded understanding. That is, skill = the art of making action free of bondage.
• Ramanuja: This buddhi-yoga while performing action is kaushal — ati-samarthya (very great capability) — that is, this buddhi-yoga is attained through a highly trained capability.

Its meaning today. The modern sense of "skill in action" — doing work well — is included in it too; but the Gita's deeper meaning is: doing work in such a way that it does not bind you.