What does the phrase El Olam mean? In Psalm 90:1-2, it says Lord [Adonai], you have been our dwelling place throughout all generations. Before the mountains were born or you brought forth the whole world, from everlasting [olam] to everlasting [olam] you are God [El].
The website, “Discovering the Jewish Jesus” beautifully describes the meaning of this name for God:
“This name teaches us that God created time, yet exists outside of and beyond it. Before the creation of the universe there was God with no beginning and no end. All things we know of change through time, yet our Father never does. This means the character of God, His Word, His Kingdom, and all He stands for never change and never end. That means we have an unceasing, dependable, trustworthy and consistent God! God has eternity in view for you. Psalm 90:1-2 ‘Lord, You have been our dwelling place for all generations…even from everlasting to everlasting, You are God [El Olam].’ He is the same yesterday, today, and forever.”
We first read of this name in Genesis 21. Abraham had dug a well, but the servants of Abimelek had seized it. Abraham was able to convince Abimelek that he had indeed dug the well (maybe all the “gifts” given to Abimelek influenced his decision?), and Abimelek returned the well to Abraham. Verse 33 says, “Abraham planted a tamarisk tree in Beersheba, and there he called on the name of the LORD [YHWH], the Eternal God [El Olam].”
Why use the name Eternal God [El Olam] here? Some suggest it was a reminder to himself that God had promised the land to him and to his descendants forever. Or perhaps it was simply as a reminder to himself that the same God who had promised the land to him would never change. Ever.
Here are just a few of the verses that refer to our God as the everlasting God:
Isaiah 26:4 – Trust in the LORD [YHWH] forever, for the LORD [YHWH], the LORD [YHWH] himself, is the Rock eternal [Olam].
Isaiah 40:28 – Do you not know? Have you not heard? The LORD [YHWH] is the everlasting God [Olam Elohim], the Creator of the ends of the earth. He does not grow tried or weary, and his understanding no one can fathom.
Jeremiah 10:10 – But the LORD [YHWH] is the true God [Elohim]; he is the living God [Elohim], the eternal [Olam] King.
As you meditation on the name El Olam, the Everlasting God, remember that the same God who made promises to Abraham and his descendants has made promises to His children throughout all ages—including today. And God never changes!
Malachi 3:6 says, “I the LORD [YHWH] do not change.” Hebrews 13:8 tells us “Jesus Christ is the same yesterday and today and forever.”
So His promises are as true today as they were thousands of years ago.
Psalm 25:6 – Remember, LORD (YHWH), your great mercy and love, for they are from of old (olam).
Psalm 100:5 – for the LORD (YHWH) is good and his love endures forever (olam); his faithfulness continues through all generations.
Psalm 103:17 – but from everlasting (olam) to everlasting (olam) the LORD’s [YHWH’s] love is with those who fear him, and his righteousness with their children’s children.
It is because of the everlasting, unchanging nature of El Olam that we can know with assurance that God is working in us to conform to the image of His Son (Romans 8:29), and that “he who began a good work in you will carry it to completion” (Philippians 1:6).
 Discovering the Jewish Jesus, https://discoveringthejewishjesus.com/el-olam/