SB 11.18.12
Devanāgarī
यदा कर्मविपाकेषु लोकेषु निरयात्मसु । विरागो जायते सम्यङ् न्यस्ताग्नि: प्रव्रजेत्तत: ॥ १२ ॥
Text
yadā karma-vipākeṣu lokeṣu nirayātmasu virāgo jāyate samyaṅ nyastāgniḥ pravrajet tataḥ
Synonyms
yadā—when;karma—by fruitive activities;vipākeṣu—in all that which is obtained;lokeṣu—including promotion to all the planets of the universe up to Brahmaloka;niraya-ātmasu—planets that are actually hellish, being material;virāgaḥ—detachment;jāyate—is born;samyak—completely;nyasta—giving up;agniḥ—the sacrificial fire ofvānaprastha;pravrajet—one should takesannyāsa;tataḥ—at that point.
Translation
If the vānaprastha, understanding that even promotion to Brahmaloka is a miserable situation, develops complete detachment from all possible results of fruitive activities, then he may take the sannyāsa order of life.