Who said "Timmy's heart is pure and true."?

This quote is attributed to Timmy.

Timmy's heart is pure and true. - Timmy

"Timmy's heart is pure and true."

Timmy Truth

"Timmy!"

"Timmy timmy timmy!"

"Timmeh!"

"Timmy loves his friends."

"Lucy, you got some 'splainin' to do!"

"You must always be honest with the people you love."

"Truth always comes out in the end."

"Honesty is always the best policy."