Who is the rock of salvation?

Deuteronomy 32:4 NWT

The Rock, perfect is his activity,
For all his ways are justice.
A God of faithfulness who is never unjust;
Righteous and upright is he.

Who is "The Rock"?
Deuteronomy 32:15-18 NWT

When Jeshʹu·run grew fat, he kicked out rebelliously.
You have grown fat, you have become stout, you have become bloated.
So he forsook God, who made him,
And despised the Rock of his salvation.

They incited him to fury with foreign gods;
They were offending him with detestable things.
They were sacrificing to demons, not to God,
To gods that they had not known,
New ones that came along recently,
To gods that your forefathers did not know.
You forgot the Rock who fathered you,
And you did not remember the God who gave birth to you.

Who did they offend?
How did they offend him?
Who is the spiritual rock that followed Moses and the Israelites?
Psalm 18:2 NWT

Jehovah is my crag and my stronghold and the One who rescues me.
My God is my rock, in whom I take refuge,
My shield and my horn of salvation, my secure refuge.

Psalm 18:30-31 NWT

The way of the true God is perfect;
The saying of Jehovah is refined.
He is a shield to all those taking refuge in him.
For who is a God besides Jehovah?
And who is a rock except our God?

Exodus 17:6 NWT

Look! I will be standing before you there on the rock in Horʹeb. You must strike the rock, and water will come out of it, and the people will drink it.” Moses did so before the eyes of the elders of Israel.

What does the rock with living water flowing from it represent?
Numbers 20:7-12 NWT

Then Jehovah said to Moses: “Take the rod and call the assembly together, you and Aaron your brother, and speak to the crag before their eyes that it may give its water, and you will bring out water for them from the crag and give the assembly and their livestock something to drink.” So Moses took the rod from before Jehovah, just as He had commanded him. Then Moses and Aaron called the congregation together before the crag, and he said to them: “Hear, now, you rebels! Must we bring out water for you from this crag?” With that Moses lifted his hand up and struck the crag twice with his rod, and much water began to pour out, and the assembly and their livestock began to drink. Jehovah later said to Moses and Aaron: “Because you did not show faith in me and sanctify me before the eyes of the people of Israel, you will not bring this congregation into the land that I will give them.”

Why did Jehovah punish Moses for striking the rock twice?
1 Corinthians 10:1-4 NWT

Now I want you to know, brothers, that our forefathers were all under the cloud and all passed through the sea and all got baptized into Moses by means of the cloud and of the sea, and all ate the same spiritual food and all drank the same spiritual drink. For they used to drink from the spiritual rock that followed them, and that rock meant the Christ.