Does God Make Useless Things?

And Hannah spoke on her heart.
Question:  Why the   phrase on her heart instead of
        the common  phrase to her heart?
Answer:   Hannah spoke to God concerning
        matters that were of her heart.

Hanna

Master of the Universe, of all the organs you created in a woman, you have not created one in vain. (Every organ fulfills its purpose) Eyes to see, ears to hear, a nose to smell, a mouth to speak, hands with which to perform labor, feet with which to walk, breasts with which to nurse. If so, these breasts that You placed upon my heart, to what purpose did You place them? Was it not in order to nurse with them? Grant me a son and I will nurse with them.