Bg 2.55

sri-bhagavan uvaca
prajahati yada kaman
sarvan partha mano-gatan
atmany evatmana tustah
sthita-prajñas tadocyate

Word for word: 
sri-bhagavan uvaca — the Supreme Personality of Godhead said; prajahati — gives up; yada — when; kaman — desires for sense gratification; sarvan — of all varieties; partha — O son of Prtha; manah-gatan — of mental concoction; atmani — in the pure state of the soul; eva — certainly; atmana — by the purified mind; tustah — satisfied; sthita-prajñah — transcendentally situated; tada — at that time; ucyate — is said.

Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The Supreme Personality of Godhead said: O Partha, when a man gives up all varieties of desire for sense gratification, which arise from mental concoction, and when his mind, thus purified, finds satisfaction in the self alone, then he is said to be in pure transcendental consciousness.

Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The Bhagavatam affirms that any person who is fully in Krishan consciousness, or devotional service of the Lord, has all the good qualities of the great sages, whereas a person who is not so transcendentally situated has no good qualifications, because he is sure to be taking refuge in his own mental concoctions. Consequently, it is rightly said herein that one has to give up all kinds of sense desire manufactured by mental concoction. Artificially, such sense desires cannot be stopped. But if one is engaged in Krishan consciousness, then, automatically, sense desires subside without extraneous efforts. Therefore, one has to engage himself in Krishan consciousness without hesitation, for this devotional service will instantly help one onto the platform of transcendental consciousness. The highly developed soul always remains satisfied in himself by realizing himself as the eternal servitor of the Supreme Lord. Such a transcendentally situated person has no sense desires resulting from petty materialism; rather, he remains always happy in his natural position of eternally serving the Supreme Lord.