Exhausted by the labor of childbirth, Yaśodā was overwhelmed with sleep and unable to understand what kind of child had been born to her.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
यशोदा नन्दपत्नी च जातं परमबुध्यत । न तल्लिङ्गं परिश्रान्ता निद्रयापगतस्मृतिः
yaśodā nandapatnī ca jātaṃ paramabudhyata | na talliṅgaṃ pariśrāntā nidrayāpagatasmṛtiḥ
SB 10.3.53