2 Kings 13:18
And he said, Take the arrows. And he took them. And he said unto the king of Israel, Smite upon the ground. And he smote thrice, and stayed. And he said, Take the arrows. And he took them. And he said unto the king of Israel, Smite upon the ground. And he smote thrice, and stayed.
Joash took the arrows in hand and, when directed to strike the ground, struck three times and then stopped. The command to strike was a test of the king's faith and determination and resolve. Because he stopped at three, he and Israel would defeat Syria only three times rather than destroying it and overcoming it completely. Five or six strikes would have meant consuming and destroying Syria.
When God promises success and opens the way for His work, those entrusted with it must act to obtain the promised result with full energy and diligence and perseverance. The measure of success given is proportionate to the diligence put forth. Trusting God and advancing in faith even when the way seems closed is met by God opening the way. Apparent defeat can become victory when workers do not give up.