What surprise did Leah have for Daniel?

In chapter 22, Daniel returns home from watching Thacia dance at the festival. When he arrives home, Leah asks him numerous questions about the festivities and asks her brother if he thinks she is pretty. Daniel responds by saying that Leah is beautiful and elaborates on how the women danced at the festival. Leah mimics the dancing women and then tells her brother that she has a surprise for him as they sit down to enjoy an elaborate meal. Leah surprises Daniel by bringing out a woven basket full of pomegranates, juicy figs, and other foreign fruits that no Galilean has ever possessed. When Daniel asks Leah which neighbor donated the food, she confesses to her relationship with Marcus, the Roman soldier who gave them the fruit basket. Daniel immediately becomes overwhelmed with anger and threatens to kill Marcus before storming out of the home. 

Leah brings Daniel a basket of fresh fruit that she received from Marcus (chapter 22). Marcus is a Roman solider, which is extremely upsetting to Daniel, an Israelite, because he believes that he has one life goal: to help free the Israelites from their Roman oppressors (which means tyrants or even slave drivers). Daniel is so dedicated to pursuing freedom for his people that he won't even pursue a relationship with Thacia, a girl he really cares about.
Daniel's hatred toward Marcus is extreme. Though Leah is trying to be kind by sharing this fruit, her gift, Daniel becomes violent when he realizes who the gift came from. First, he spits the fruit from his mouth, and then he begins to attack Leah verbally and physically. He claims that this relationship is bringing shame to their family and forbids Leah from ever seeing Marcus again.
However, Marcus and Leah do eventually see each other again, as Marcus makes a point to see Leah again before he leaves (chapter 24). Surprisingly, Daniel invites Marcus into their home after he begins to realize that "only love could bend a bow of bronze," which is a lesson that he learned from Jesus's teachings. Daniel's behavior toward Marcus at the start of the novel was angry; he took out his frustration on his sister, threatening her and intimidating her to keep her away from Marcus, the Roman soldier. By the end of the novel, David is released from his anger and bitterness. He learns that loving one's enemies is the only true path to freedom and peace.