R. Meir says: Now does this not follow a fortiori? If (even) when they anger Him they are called "sons," if they did not anger Him, how much more so!
(Ibid. 20) "And He said: I shall hide My face from them": The Holy One Blessed be He said: I shall remove My Shechinah from among you." I shall see mah acharitham": I shall know what their end will be.
Variantly: I shall relegate them to servitude in four exiles.
"for they are a generation of tahpuchoth" It is not written "tahfoch," but "tahpuchoth."