Obadiah 1:11
10 “Because you violently slaughtered your relatives, the people of Jacob, shame will cover you, and you will be destroyed forever. 11 You stood aloof while strangers took his army captive and foreigners advanced to his gates. When they cast lots over Jerusalem, you behaved as though you were in league with them. 12 You should not have gloated when your relatives suffered calamity. You should not have rejoiced over the people of Judah when they were destroyed. You should not have boasted when they suffered adversity.
Sirach 37:4
Ben Sira, Ecclesiasticus2 Is it not a sorrow like that for death itself when a dear friend turns into an enemy? 3 O inclination to evil, why were you formed to cover the land with deceit? 4 Some companions rejoice in the happiness of a friend, but in time of trouble they are against him. 5 Some companions help a friend for their stomachs' sake, yet in battle they will carry his shield.
Notes and References
"... Sirach 37:4 also contains an indirect allusion to Edom’s failure to help his brother Jacob: (“on the day that you stood aloof,” Obadiah 11) during an attack by “foreigners” (Obadiah 11). In contrast, Sirach 37:5 praises the good friend who fights against a “foreigner” ..."
Corley, Jeremy Ben Sira's Teaching on Friendship (p. 78) Brown University, 2020