Arcana Coelestia # 8614
8614. And it was, his hands were steady. That this signifies the strength of power then, is evident from the signification of “hands,” as being power (see above, n. 8612). Hence the strength of power is signified by the hands being made steady through being held up.
Exodus 17:10-13
10
So Joshua did as Moses had told him, and fought with Amalek; and Moses, Aaron, and Hur went up to the top of the hill.
11
It happened, when Moses held up his hand, that Israel prevailed; and when he let down his hand, Amalek prevailed.
12
But Moses' hands were heavy; and they took a stone, and put it under him, and he sat on it. Aaron and Hur held up his hands, the one on the one side, and the other on the other side. His hands were steady until sunset.
13
Joshua defeated Amalek and his people with the edge of the sword.