Oyeku (|| || || ||) is the first of the sixteen Odu of Ifa oracle divination system. It is comprised of four double lines; each double line represents the split side of a cowrie shell, and the four double lines are the split sides of four cowries.
Each Odu is equal to 4 bits (binary digits). A double line in an Odu or the split side of a cowrie is equal to 0 and a single line or the smooth side of a cowrie is equal to 1.
Therefore, the four double lines (four split sides) in Oyeku are equal to 0000.