When a devotee becomes like a person haunted by a ghost, he laughs and very loudly chants about the qualities of the Lord. Sometimes he sits to perform meditation, and he offers respects to every living entity, considering him a devotee of the Lord. Constantly breathing very heavily, he becomes careless of social etiquette and loudly chants like a madman, “Hare Kṛṣṇa, Hare Kṛṣṇa! O my Lord, O master of the universe!”
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
यदा ग्रहग्रस्त इव क्वचिद्धस- त्याक्रन्दते ध्यायति वन्दते जनम् । मुहुः श्वसन् वक्ति हरे जगत्पते नारायणेत्यात्ममतिर्गतत्रपः
yadā grahagrasta iva kvaciddhasa- tyākrandate dhyāyati vandate janam | muhuḥ śvasan vakti hare jagatpate nārāyaṇetyātmamatirgatatrapaḥ
SB 7.7.35