Teapot Atheist has compiled a nice list of 10 Bible passages (from both Testaments) where abuse of children is either permitted or expected.
4. If children make fun of your bald head, the appropriate response is to have them massacred by bears. This way, we know that in Biblical morality, punishments need no proportion to the crimes. (2nd Kings 2:23)
3. If you don’t hate your mom, your dad, your siblings, your children, and yourself, Jesus is wrong for you. So in Biblical morality, a cohesive family unit is a moral aberration. (Luke 14:26)
I should say that no parents follow these examples to the letter anymore (I hope), but it doesn’t help the case the morality comes from the bible.