Verses 65-69 of Chapter 16:

Allah sent down water from heaven, and by it gave life to the earth after it had been dead: indeed there is a Sign in this for those who listen (to the Message). And surely there is a lesson for you in the cattle: We give you to drink of that which is in their bellies between filth and blood, that is, pure milk, which is very pleasant to those who drink it. (Likewise) We give you from date-palms and vines a drink from which you derive intoxicants and also pure food: indeed there is a Sign in this for those who make use of their common sense. And behold! Your Lord has inspired the bee with this "Build thy hive in the mountains, trees and in the creepers over trellises: then drink nectar from every kind of fruit, and follow the ways made smooth by the Lord." From its belly comes out a fluid of varying hues wherein is healing for mankind. Here is indeed a Sign for those people who ponder over it.