Nehemiah 4:13 & 14
"Therefore I stationed some of the people behind the lowest points of the wall at the exposed places, posting them by families, with their swords, spears and bows. After I looked things over, I stood up and said to the nobles, the officials and the rest of the people, 'Don't be afraid of them. Remember the Lord, who is great and awesome, and fight for your brothers, your sons and your daughters, your wives and your homes.'" NIV translation
Nehemiah stations guards to protect the city but he does so by family. He then encouraged them by telling them to remember that the Lord was on their side. By stationing them by family, they were willing to fight harder to protect their own.