Ezra 8:22

For I was ashamed to require of the king a band of soldiers, &c. He might have obtained from the king any thing that he desired; but he had so openly declared that he depended solely upon God for safe conduct, that he was ashamed to ask a guard of the king to secure them on their journey from their enemies. For the king, not being much instructed in divine matters, might possibly have thought that what they had said of God's favour toward them, and the prophecies concerning their restoration, were but vain boasts, in case they had seemed to distrust the power and favour of that God of whom they had spoken so magnificently, by making application to the king for his protection and defence. Rather, therefore, than give any such umbrage, they were resolved to commit themselves entirely to God: but then it was necessary they should beseech that of him which they would not ask of the king; this they did, as we have just seen, by fasting and prayer.