The sacred name of God, called the tetragramma- ton, is spelled with four Hebrew letters: yod, hei, vav, and hei. When God changes Abram’s name to Abraham, He inserts the Hebrew letter hei from His divine name into Abram’s name. Hei is the fifth letter of the Hebrew alphabet, and the biblical number five represents grace. The letter hei also has a strong breathing sound, representing the sound of life when it is pronounced.
God also changes Sarai’s name to Sarah, inserting the second hei of His sacred name into Sarah’s name (see Gen. 17:15). Thus, after God inserts the two letters of His divine name, one into Abraham’s name and the other into Sarah’s, God gives new “life” to Sarah and Abraham, making them fruitful and giving them their son of promise.
From Page 32 of the Perry Stone Hebraic Prophetic Old Testament Study Bible
