'Oh, sharper than a brief candle it is to bury a thankless child!'

What's Shakespeare's line about a thankless child?

How something or other it is to have a thankless child?" "

Another lesson from Seaman: nothing tears at the heart like a thankless child.

Leilani never rebuked her mother for this cruelty, or for any other, because Sinsemilla would not tolerate a thankless child.

Sharper than a serpent's tooth is a thankless child.

For example (to me, frowning at my spinach): "How sharper than a serpent's tooth it is/To have a thankless child."

How sharper than a serpent's tooth it is to have a thankless child!

Or are these, indeed, thankless children?

"A thankless child is sharper than a serpent's tooth," Grady said, handing him his drink.