Garudapurana 3.12.60

3.12.60

guṇapūrṇasya viṣṇostu nirguṇatvavicintanam /
jātānandādipūrṇāṅkhyaṃ sohamityādicintanam //

Conceiving Viṣṇu, who is full of auspicious attributes, as devoid of attributes;
thinking of Him as having an उत्पन्न beginning of bliss, or thinking, 'I am He';