How does Mr. Pirzada react to the idea of Lilia going out trick or treating? what does Lilia mean when she tries to explain it to her friends by saying "his daughters are missing"?

Mr. Pirzada gets upset when he knows that Lilia will be roaming around. When Lilia talks about Mr. Pirzada daughters she means that he misses them and worries about their safety.

Explanation:

Mr. Pirzada and Lilia are friends even when they have very different ages, he remembers his own daughters back at home when he talks with Lilia, and she worries about the safety of Mr. Pirzada's family and prays for them every night, the night when Mr. Pirzada worries about Lilia is on Halloween since she's going to go asking for candy.

which book is that from