نواقض الإسلام
Ibn ‘Abbās (may Allah be pleased with him) reported that the Messenger of Allah (may Allah's peace and blessings be upon him) said: "He who acquires a branch of the knowledge of astrology learns a branch of magic of which he acquires more as long as he continues to do so."
عن ابن عباس -رضي الله عنهما- قال: قال رسول الله -صلى الله عليه وسلم-: "من اقتَبَس شُعْبَة من النُّجوم؛ فقد اقتَبَسَ شُعْبة من السِّحْر، زاد ما زاد".
شرح الحديث :
Since the unseen is known only to Allah, the Prophet (may Allah's peace and blessings be upon him) forbade all attempts to figure it out. Astrology is thus forbidden, as it is an attempt to use celestial conditions to predict terrestrial events. The Prophet (may Allah's peace and blessings be upon him) explained that learning astrology is learning a kind of magic. The more one learns of it, the more magic he learns.