'Built an Altar' in the Bible

And Moses built an altar, and he called its name Yahweh [Is] My Banner.

And Moses wrote all the words of Yahweh, and he rose early in the morning, and he built an altar at the base of the mountain and [set up] twelve memorial stones for the twelve tribes of Israel.

And Aaron saw, and he built an altar before it, and Aaron called, and he said, "A feast for Yahweh tomorrow."