Isaih, of Hebrew origin, means 'God is my salvation'. It's a variant spelling of Isaiah, which was a popular biblical name among the Israelites during ancient times. Pronounced as /i-zay/, it has gained popularity in recent years, particularly in English-speaking countries.
"The name Isiaih saw its peak popularity in the late 1990s to early 2000s, with a high of 16 births in 2000 and consistent high teens or twenties until 2004. However, it has since declined, reaching just 5 births again in 2010."