1 Chronicles 20:4
And it came to pass after this, that there arose war at Gezer with the Philistines; at which time Sibbechai the Hushathite slew Sippai, that was of the children of the giant: and they were subdued. And it came to pass after this, that there arose war at Gezer with the Philistines; at which time Sibbechai the Hushathite slew Sippai, that was of the children of the giant: and they were subdued.
After this there arose war at Gezer with the Philistines, in which Sibbechai the Hushathite slew Sippai, who was of the children of the giant, and they were subdued. Sippai belonged with Lahmi and the man of great stature with six fingers and six toes described in the following verses. Sippai with those others was a brother of Goliath, and these relatives of Goliath were killed by David and his servants.
When a crisis comes that is beyond human strength, God's people are to seek His help together, as Judah did when Jehoshaphat proclaimed a fast and the people gathered together to seek the Lord. That gathering shows united seeking of the Lord in time of helplessness. The same example is followed when believers in separate communities each give themselves to prayer at the same time of need.