Al Sharatain is the first of the twenty-eight lunar mansions, the manazil al-qamar, the stations through which the Moon passes in its monthly circuit as reckoned in the Arabic and later Western tradition. These are distinct from the twenty-seven Vedic nakshatras, though both divide the ecliptic by the Moon: here the circle is cut into twenty-eight segments of roughly 12 degrees 51 minutes each, and this mansion opens the series at 0 degrees. Its name refers to the two horns of the Ram, the stars beta and gamma Arietis. In the manazil tradition its planetary ruler is the Sun, and its traditional talismanic virtue is given as journeys and discord. The magical use of the mansions, engraving an image while the Moon stands in a given station, was transmitted through the Picatrix and Agrippa. These are the conventions of that talismanic tradition rather than statements about the stars.
The relationship between this system and its two sibling lunar-zodiacs deserves an honest account, since it remains a genuinely open scholarly question. The twenty-eight Arabic manazil, the twenty-seven Indian nakshatras, and the twenty-eight Chinese xiu all divide the ecliptic by the Moon's own monthly circuit, and Babylonian astronomy is often proposed as a common ancestor behind all three, but the transmission history has never been settled, scholars having argued for transmission in more than one direction and for independent development from a shared source. The manazil also carry their own medieval Arabic layer distinct from the other two: the anwa', a pre-Islamic system of weather and farming timing keyed to stars' heliacal rising. These stations have sometimes been mislabelled Vedic elsewhere; the manazil are Arabic, close to but distinct from the Indian nakshatras.