All the learned scholars have given their opinion. The mind is by nature very restless, and one should not make friends with it. If we place full confidence in the mind, it may cheat us at any moment. Even Lord Śiva became agitated upon seeing the Mohinī form of Lord Kṛṣṇa, and Saubhari Muni also fell down from the mature stage of yogic perfection.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
तथा चोक्तं - न कुर्यात्कर्हिचित्सख्यं मनसि ह्यनवस्थिते । यद्विश्रम्भाच्चिराच्चीर्णं चस्कन्द तप ऐश्वरम्
tathā coktaṃ - na kuryātkarhicitsakhyaṃ manasi hyanavasthite | yadviśrambhāccirāccīrṇaṃ caskanda tapa aiśvaram
SB 5.6.3