The term 'Observe Ramadan, Say' can be summarized as a call to observe the Islamic holy month of Ramadan and to recite the Islamic declaration of faith known as the Shahada. Ramadan is a time of fasting, prayer, and reflection for Muslims, and is one of the five pillars of Islam. The word 'FAST' in this crossword solution refers to the practice of fasting during Ramadan, which is an important part of the observance.