"How sharper than a serpent's tooth it is to have a thankless child" Literal meaning - it is especially painful for parents to raise an ungrateful child. Origin From Shakespeare's King Lear, 1605 LEAR: It may be so, my lord. Hear, nature, hear; dear goddess, hear! Suspend thy purpose, if thou didst intend To make this creature fruitful! Into her womb convey sterility! Dry up in her the organs of increase; And from her derogate body never spring A babe to honour her! If she must teem, Create her child of spleen; that it may live, And be a thwart disnatured torment to her! Let it stamp wrinkles in her brow of youth; With cadent tears fret channels in her cheeks; Turn all her mother's pains and benefits To laughter and contempt; that she may feel How sharper than a serpent's tooth it is To have a thankless child! Away, away!

Hey, Safaa! The meaning of this motto is: -For the parents, to have a bad son/daughter (A son/daughter who doesn't respect them and doesn't have the feeling of gratitude for them) hurts them more than if they were bitten by a snake... ^__^