The Hamsa (Arabic: Khamsa;, literally "five", Hebrew: חמסה , Khamsa;) is a symbol used in amulets, charms and jewelry to protect against the "evil eye."
An alternative Islamic name for this charm is the Hand of Fatima or Eye of Fatima, in reference to Fatima Zahra, the daughter of Muhammad. An alternative Jewish name is the Hand of Miriam, in reference to Miriam, the sister of Moses and Aaron. It is a kind of "protecting hand" or "hand of God".
Some associate the significance of the five fingers to the five books of the Torah for Jews, the Five Pillars of Islam for Sunnis, or the five People of the Cloak for Shi'ites. This symbolism may have evolved at a later stage, in view of the fact that archaeological evidence suggests the hamsa predates both religions.
In recent years some activists for Middle East peace have chosen to wear the hamsa as a symbol of the similarities of origins and tradition between the Islamic and Jewish faiths. The fingers can point up or down.

Arab custom

The hamsa is widespread in Arab countries, and is sold in many different forms especially in the marketplaces of Egypt, Morocco, Algeria and Tunisia. It is often painted on the fronts of homes. Nevertheless, many Arabs, Christian and Muslim, regard this as a superstition. They believe that only God protects them, and the hamsa is tantamount to shirk, or idolatry. The symbol may have originated in Punic religion, where it was associated with Tanit. Hamsa plaques, often made of turquoise-colored ceramics, are very common in modern Egypt. The Hamsa is a protection or "magical pendant".

Jewish custom

Clay hamsa on a wall, inscribed with the Hebrew word "behatzlacha"" - literaly "Good Luck" or "May you succeed"
Hamsas are popular as charms and decorations in Israel and are not considered to have any Islamic connection other than the shared Arabic name (same as the Hebrew). Among Jews, fish are considered to be a symbol of good luck, so many hamsas are also decorated with fish images. Hamsas are incorporated in wall plaques, mobiles, keychains and necklaces. Sometimes they are inscribed with Hebrew prayers, such as the Sh'ma, the Birkat HaBayit (Blessing for the Home), or the Tefilat HaDerech (Traveler's Prayer). Hamsas may be displayed in either directon, up or down according to the taste or decoration associated with the Hamsa.