In Mark 7:14–15, Jesus says the following: "'Listen to me, all of you, and understand: there is nothing outside a person that by going in can defile, but the things that come out are what defile.'". His disciples fail to understand, so once they are alone with Jesus, they ask him about it, and Jesus elaborates as follows: "Do you not see that whatever goes into a person from outside cannot defile, since it enters, not the heart but the stomach, and goes out into the sewer? ... It is what comes out of a person that defiles. For it is from within, from the human heart, that evil intentions come."[] In the middle of this speech, the author of the Gospel of Mark writes explicitly that in saying these things, Jesus "declared all foods clean".