Fasting...

So I am fasting today to prepare for a medical procedure i have to have done tomorrow and it stinks!  I am getting hungry and weak and my mind begins to wonder....  I can see how one would be able to get something spiritual out of fasting now... not that this is a spiritual fast, but I can see how one might get something out of it in prayer constantly.  Learning to depend on the Father for strength and not relying on bread alone.  I always wondered how you could learn something while fasting, i thought "that's silly, shouldn't you nourish your body while trying to grow spiritually"  but its quite the contrary and i see that now.  This is only a 36hour fast and I did one last summer for a medical procedure too, so i am confident i can make it through the next couple days, but now I am intrigued.  What might come of a spiritual fast for me?  Would God tell me to fast? I know it has to come from God and you have to be very purposeful and intentional when fasting, and i know about some of the different types of fasting, but i have no idea what God could do with me if I was fasting for Him!    Our strength needs to come from our Heavenly Father only and we tend to rely on ourselves and our world for our nourishment.  Thank you Father for revealing something about yourself to me today and for growing me daily!