Senāsanakkhandhaka

Vinayapiṭaka · Cūḷavagga (2) · Vol. 7 · Section 249

[249] The brahmin who has attained final Nibbāna (parinibbuto) ever sleeps at ease; one who is not smeared by sensual pleasures, grown cool, free of acquisitions (nirūpadhi). Having cut off all attachments (āsatti), having dispelled the anguish in the heart, at peace, he sleeps at ease, having attained the peace of mind (citta).

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.