CC Ādi 5.31

brahma-sāyujya-muktera tāhā nāhi gati
vaikuṇṭha-bāhire haya tā’-sabāra sthiti
Word for word: 
brahma-sāyujya — of merging into the Supreme Brahman; muktera — of the liberation; tāhā — there (in Vaikuṇṭha); nāhi — not; gati — entrance; vaikuṇṭha-bāhire — outside the Vaikuṇṭha planets; haya — there is; tā’-sabāra sthiti — the residence of all of them.
Translation: 
Those who attain brahma-sāyujya liberation cannot gain entrance into Vaikuṇṭha; their residence is outside the Vaikuṇṭha planets.