A well-slept child is a well-grown child, I guess.
2022 August 4, Isshiki Ichika, fame, Berserk of Gluttony (Light Novel) Vol. 7, Seven Seas Entertainment, →ISBN:
... A well-slept child is a well-kept child, or so the saying went. But at present, I needed her awake. “Hey! We don't have time for a nap!” I said. I gave the axe a few knocks, and finally Sloth woke with a great yawn. How could she sleep[…]
2023 February 20, Kazuki Amamiya, Haibara's Teenage New Game+ Volume 2, J-Novel Club, →ISBN:
"They do say a well-slept child is a well-kept child, and that's important for you, Uta." "Um, Natsu? What're you trying to say?" she sounded a bit sullen. "I've been growing bit by bit lately." "Really? That's great to hear."
