When studying mystical texts, the reader finds out that along with mystic's loving relationship with God, which is characterized by resort, absorption, submission and, finally, destruction, there is another relationship, which appears to be irrespective of the holy and unholy sanctum. Coexistence of these two opposites confuses readers of mystical texts. Investigating the quotes and actions of ten famous Islamic mystics – from Rabe‘eh to Rumi –, the present study examines the types, manifestations and reasons of taboo-breaking in mystical texts. In mystical texts, taboo breaking exists in two forms: "denial of distance" and "fighting the medium" in respect to the holy and unholy. It includes various topics such as sense of union with God, expressing equality with God, fasting and praying, Satan, etc. A deeper search for causes of taboo-breaking indicates that although some instances taboo-breaking or mystic’s impudence seem to be a protest against the distortion of values, in most cases it is the result of the mystic's intimacy with God. Therefore, it is not in contradiction with his submission to Him.