John Gill Commentary Joshua 8:26

"For Joshua drew not back his hand, wherewith he stretched out the javelin, until he had utterly destroyed all the inhabitants of Ai." — Joshua 8:26 (ASV)

For Joshua drew not his hand back wherewith he stretched out
his spear
But continued it, and that stretched out:

until he had utterly destroyed all the inhabitants of Ai ;
just as the hand of Moses was held up, and kept held up until Amalek was discomfited by Joshua, (Exodus 17:12Exodus 17:13) .