Numbers 32:24

Build you cities for your little ones, and folds for your sheep; and do that which hath proceeded out of your mouth.

Moses directed the tribes of Gad and Reuben to provide fortified cities to shelter their children and enclosures to protect their flocks before they crossed over to fight alongside the rest of Israel. The further charge to carry out what had come from their own lips placed them under solemn obligation to keep their word and remain with their brethren in the warfare until every tribe had secured its allotted inheritance. In the same way the verse requires those who profess Christ not to settle into personal comfort and advantage while shifting the labor, sacrifice, and hardship of God's work onto others.