He does not change. Malachi 3:6
And that verse is misquoted as well.
God does not change in character, nature etc. He often changes how he acts.
For example, God told Moses to build a Tabernacle. None of the Patriarchs did that; if God spoke to them or they had a sacred experience, they built an altar/set up a stone, worshipped him and then moved on. Suddenly, God was being "carried around" so that he would be with people where they were.
Then God told Solomon to build a Temple - and the tabernacle was not heard of again, (though the ark of the covenant was.) That Temple was destroyed and another one was built, and later IT was destroyed.
Nowadays, God lives in the hearts of his children, who are temples of the Holy Spirit.
Or consider sacrifices. Many thousands of animals were being sacrificed for sin, as God commanded Moses. Then, he sent Jesus to die for us and Paul wrote that the blood of bulls and sheep cannot atone for sin.
God told Moses to tell the Hebrew slaves not to eat pork or shrimp. Yet Paul said that the kingdom of God is not a matter of eating and drinking. Mark commented that "in saying this, Jesus declared all foods to be clean."
God told people not to worship idols. Yet Paul said that an idol is nothing and if someone wants to eat meat offered to an idol, they can - as long as it does not lead other people astray.
God told the prophets that he would punish people for their sins. But some listened, e.g. Nineveh, and he didn't. Abraham pleaded for the city of Sodom who were ging to be destroyed, and he got God to agree that if there were 50, 40, 30, even 10 righteous people, the city would be saved. Sadly, there weren't even that number, but the point is that God wasn't so fixed in his plans that he wasn't prepared to change them if the circumstances were different.
God himself said to Isaiah, "see, I am doing a
new thing", Isaiah 43:19. He told Jeremiah he would make a
new covenant, and the book of Hebrews said that where there is a new covenant, the old one becomes obsolete and will soon disappear.
He told Ezekiel that he would put a new spirit in people.
Revelation says that there is to be a new heaven and a new earth.