This book explains the reality of Tawḥīd al-Ulūhiyyah, or al-ʿIbādah (strict, pure monotheism in worship) and makes mention of its rulings, limits, conditions, excellence, evidences, foundations...

Indeed, it is true misguidance that you acknowledge what you used to reject [as error, falsehood) and you reject what you used to acknowledge [as truth].