'Built an Altar' in the Bible

And Moses built an altar, and called the name of it Jehovah My Banner.

And Moses wrote all the Words of Jehovah, and rose up early in the morning, and built an altar below the mountain and twelve pillars according to the twelve tribes of Israel.

And when Aaron saw, he built an altar before it. And Aaron made proclamation and said, Tomorrow is a feast to Jehovah.