Midrash su Ezechiele 23:31

(Devarim 32:5) "Shicheth lo lo. Banav mumam": Even though they are full of blemishes, they are still called sons (banim). These are the words of R. Meir. And thus was R. Meir wont to say: If when they are full of blemishes they are called "banim," if they are unblemished, how much more so! Similarly (Isaiah 1:4) "evil seed, corrupt sons": If when they are corrupt they are called "sons," if they were not corrupt, how much more so! Similarly, (Jeremiah 4:22) "They are wise to do evil": Now does this not follow a fortiori? If they do evil they are called "wise," how much more so, if they do good! Similarly, (Ibid.) "They are foolish sons, and not understanding": Does this not follow a fortiori? If when they are foolish, they are called "sons," how much more so, if they were understanding! Similarly, (Ezekiel 23:31) "And they come to you as a people comes, and My people sit before you and hear your words": I might think, they hear and fulfill; it is, therefore, written (Ibid.) "but they do not fulfill them." Now does this not follow a fortiori? If when they hear and do not fulfill they are called "My people," how much more so, when they hear and fulfill!