What prompted Daniel to lead the slave, and why did he later regret this?

When Rosh's band attacks the passing merchant caravan and steals the slave, Joel has just come up to the mountain to get a glimpse of Rosh. Daniel introduces Rosh to Joel, and Rosh seems suitably impressed with him. Daniel actually becomes jealous because Rosh is paying attention to Joel and does not acknowledge Daniel's role in the successful raid. Referring to the slave, Rosh gives the order to "bring him along," and Daniel makes the...

When Rosh's band attacks the passing merchant caravan and steals the slave, Joel has just come up to the mountain to get a glimpse of Rosh. Daniel introduces Rosh to Joel, and Rosh seems suitably impressed with him. Daniel actually becomes jealous because Rosh is paying attention to Joel and does not acknowledge Daniel's role in the successful raid. Referring to the slave, Rosh gives the order to "bring him along," and Daniel makes the first move to grab the slave's chain. Later he realizes why he did so: "It had been nothing but a boast, an urge to make up for the fact that Joel had found favor with Rosh." 

He almost immediately regrets doing so, however, because the slave can only move very slowly because of the manacles on his feet. That means that the others can scramble up the mountainside, but Daniel and the slave take much longer to get to camp, arriving after dark and after most of the other men have finished eating. Then, instead of being able to sit down and eat like the other men, Daniel finds that he is now the slave's caretaker by default, and he has to serve the slave by getting him water and food and then taking off his manacles. It is hard work to remove the double-thick ankle chains, and Daniel stays up well into the night to do so, becoming fatigued and irritable. When he finally frees Samson from his chains, however, Samson repays him by falling down in homage before him. Daniel is embarrassed by this show of allegiance. The slave then follows Daniel to his sleeping place, and Daniel again cares for him by finding him a cloak to sleep under. Daniel regrets the extra work the slave causes him, but Daniel's kindnesses, however grudging, result in Samson saving his life later on.