Bg 18.4

niscayam srnu me tatra
tyage bharata-sattama
tyago hi purusa-vyaghra
tri-vidhah samprakirtitah

Word for word: 
niscayam — certainty; srnu — hear; me — from Me; tatra — therein; tyage — in the matter of renunciation; bharata-sat-tama — O best of the Bharatas; tyagah — renunciation; hi — certainly; purusa-vyaghra — O tiger among human beings; tri-vidhah — of three kinds; samprakirtitah — is declared.

Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
O best of the Bharatas, now hear My judgment about renunciation. O tiger among men, renunciation is declared in the scriptures to be of three kinds.

Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Although there are differences of opinion about renunciation, here the Supreme Personality of Godhead, Sri Krishna, gives His judgment, which should be taken as final. After all, the Vedas are different laws given by the Lord. Here the Lord is personally present, and His word should be taken as final. The Lord says that the process of renunciation should be considered in terms of the modes of material nature in which it is performed.