How accurate is the attribution of the three levels of fasting (ordinary, special, and extra-special) to Imam Al-Ghazali, which include abstaining from things that break the fast, safeguarding the bodily organs, and the heart fasting from other than God?

Fasting has three levels: the general fast by refraining from food and sexual intimacy; the special fast by restraining the limbs from sins; and the most special fast by purifying the heart from base thoughts, worldly concerns, and anything other than Allah. People vary in their fasting. The deficient fast is abstaining from food and drink while allowing the tongue and limbs to engage in unlawful acts. This is a weak fast, and there is concern that it may not benefit its practitioner. The true fast is safeguarding the limbs from unlawful acts. As for the heart's fast, it is a great level attained only by those granted divine success. The Muslim is required to achieve the most complete degrees of fasting, and people differ in this.