Contradiction with Genesis 36:12
Mentions Timna as a concubine and mother of Amalek, while Psalms 83:7 lists her offspring among the enemies.
Genesis 36:12: And Timna was concubine to Eliphaz Esau's son; and she bare to Eliphaz Amalek: these [were] the sons of Adah Esau's wife.
Contradiction with Exodus 17:16
God declares war against Amalek from generation to generation, contradicting any alliance as implied in Psalms 83:7.
Exodus 17:16: For he said, Because the LORD hath sworn [that] the LORD [will have] war with Amalek from generation to generation. [Because...: or, Because the hand of Amalek is against the throne of the LORD, therefore, etc] [the LORD hath...: Heb. the hand upon the throne of the LORD]
Contradiction with 1 Samuel 15:2-3
God instructs Saul to utterly destroy the Amalekites, a conflicting action against their association in Psalms 83:7.
1 Samuel 15:2-3: Thus saith the LORD of hosts, I remember [that] which Amalek did to Israel, how he laid [wait] for him in the way, when he came up from Egypt.
Contradiction with Deuteronomy 25:17-19
Commands the Israelites to blot out the remembrance of Amalek, contrasting with the alliance listed in Psalms 83:7.
Deuteronomy 25:17-19: Remember what Amalek did unto thee by the way, when ye were come forth out of Egypt;