Might Jesus have referred in a general sense to any Christian who builds up his brothers with spiritual nourishment? God told the nation of Israel: “You are my witnesses... even my servant whom I have chosen. ”
قَالَ ٱللهُ لِأُمَّةِ إِسْرَائِيلَ :‏ « أَنْتُمْ شُهُودِي .‏ .‏ .‏