For the conditioned souls, the human body is most difficult to achieve, and it can be lost at any moment. But I think that even those who have achieved human life rarely gain the association of pure devotees, who are dear to the Lord of Vaikuṇṭha.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
दुर्लभो मानुषो देहो देहिनां क्षणभङ्गुरः । तत्रापि दुर्लभं मन्ये वैकुण्ठप्रियदर्शनम्
durlabho mānuṣo deho dehināṃ kṣaṇabhaṅguraḥ | tatrāpi durlabhaṃ manye vaikuṇṭhapriyadarśanam
SB 11.2.29