Amos 1:9

Thus saith the LORD; For three transgressions of Tyrus, and for four, I will not turn away [the punishment] thereof; because they delivered up the whole captivity to Edom, and remembered not the (k) brotherly covenant:

(k) For Esau (from whom came the Edomites) and Jacob were brothers, therefore they ought to have admonished them by their brotherly friendship, and not to have provoked them to hatred.