Srimad-Bhagavatam: Canto 10 - Chapter 1 - Verse 35-36
पूतना लोकबालघ्नी राक्षसी रुधिराशना ।जिघांसयापि हरये स्तनं दत्त्वाप सद्गतिम् ॥ ३५ ॥किं पुन: श्रद्धया भक्त्या कृष्णाय परमात्मने ।यच्छन् प्रियतमं किं नु रक्तास्तन्मातरो यथा ॥ ३६ ॥
pūtanā loka-bāla-ghnīrākṣasī rudhirāśanājighāṁsayāpi harayestanaṁ dattvāpa sad-gatim
Pūtanā was always hankering for the blood of human children, and with that desire she came to kill Kṛṣṇa; but because she offered her breast to the Lord, she attained the greatest achievement. What then is to be said of those who had natural devotion and affection for Kṛṣṇa as mothers and who offered Him their breasts to suck or offered something very dear, as a mother offers something to a child?
Pūtanā had no affection for Kṛṣṇa; rather, she was envious and wanted to kill Him. Nonetheless, because with or without knowledge she offered her breast, she attained the highest achievement in life. But the offerings of devotees attracted to Kṛṣṇa in parental love are always sincere. A mother likes to offer something to her child with affection and love; there is no question of envy. So here we can make a comparative study. If Pūtanā could attain such an exalted position in spiritual life by neglectfully, enviously making an offering to Kṛṣṇa, what is to be said of mother Yaśodā and the other gopīs, who served Kṛṣṇa with such great affection and love, offering everything for Kṛṣṇa’s satisfaction? The gopīs automatically achieved the highest perfection. Therefore Śrī Caitanya Mahāprabhu recommended the affection of the gopīs, either in maternal affection or in conjugal love, as the highest perfection in life (ramyā kācid upāsanā vrajavadhū-vargeṇa yā kalpitā).