Exodus 17:13 BBE

¹¹  Now while Moses' hand was lifted up, Israel was the stronger: but when he let his hand go down, Amalek became the stronger.

¹²  But Moses' hands became tired; so they put a stone under him and he took his seat on it, Aaron and Hur supporting his hands, one on one side and one on the other; so his hands were kept up without falling till the sun went down.

¹³  And Joshua overcame Amalek and his people with the sword.

¹⁴  And the Lord said to Moses, Make a record of this in a book, so that it may be kept in memory, and say it again in the ears of Joshua: that all memory of Amalek is to be completely uprooted from the earth.

¹⁵  Then Moses put up an altar and gave it the name of Yahweh-nissi: