One instance of wisdom in fasting in Ramadan with respect to training the instinctual soul is as follows:
The instinctual soul wants to be free and independent, and considers itself to be thus. According to the dictates of its nature, it even desires an imaginary dominicality and to act as it pleases. It does not want to admit that it is being sustained and trained through innumerable bounties. Especially if it possesses wealth and power in this world, and if heedlessness also encourages it, it will devour God's bounties like a usurping, thieving animal.
Thus, in the month of Ramadan, the instinctual soul of everyone, from the richest to the poorest, may understand that it does not own itself, but is totally owned; that it is not free, but is a slave. It understands that if it receives no command, it is unable to do the simplest and easiest thing, it cannot even stretch out its hand towards water. Its imaginary dominicality is therefore shattered; it performs its worship and begins to offer thanks, its true duty.
Bediuzzaman Said Nursi / Risale-i Nur Collection / The Letters