Hos 2:1

“"Tell your brothers and sisters, my people, that they have attained mercy." LXX: "Say to your brother, my people, and to your sister, having obtained mercy." Because the day of Jezrael is great, on which Judas and Israel will have one prince, and it will not be said of Israel, "you are not my people," but on the contrary they will be called the children of the living God. Therefore, O men of the tribe of Judah, do not despair of the ten tribes' salvation, but daily provoke them to repentance by speech, prayer, vow and letters because they are your brothers and sisters: brothers because they are called "my people," sisters because they are called "having obtained mercy." Otherwise: You who believe in Christ, being both from the Jews and from the Gentiles, say to those who have been cut off and to the former people, "You are my people," because they are your brothers, and "having obtained mercy" because they are your sisters. "For when the fullness of the Gentiles has entered, then all Israel shall be saved." (Romans 11:25). The same thing is prescribed to us, that we do not completely despair of heretics, but that we provoke them to penance: and we desire their salvation with the affection of brotherhood.”