Genesis 20:7 is the final piece of God's word to Abimelech in the dream. Targum Pseudo-Jonathan:
"And now let the wife of the man return; for he is a prophet; he will pray for thee, and thou shalt live: but if thou wilt not let her return, know that dying thou shalt die, thou and all who are thine."
Notice the astonishing instruction. God has just finished telling Abimelech that Abraham lied to him, endangered him, and triggered this whole mess — and in the same breath God calls Abraham a navi, a prophet, and tells Abimelech that Abraham will pray for him and his household will live.
This is the first time the word prophet appears in the Torah. It does not appear in the context of Abraham's greatest moment. It appears in the context of Abraham's most embarrassing moment — during the second time he lies about his wife to save his own skin. The rabbis of Bereshit Rabbah were not shy about pointing this out. Prophecy is not a reward for perfection. It is a designation of function. Abraham prays, and his prayer is heard. That is what makes him a prophet.
And the prophet's first job, on his first appearance in Torah under that title, is to pray for the healing of the very king he has wronged. Genesis 20:17 will close the chapter with Abraham doing exactly that: "Abraham prayed to God, and God healed Abimelech and his wife and his maidservants."
The Targum is making a quiet but radical point. Prophetic power in Judaism is not primarily about prediction or ecstatic vision. It is about the ability to carry other people's needs before the throne of the Holy One and be heard.
The takeaway: the mark of the prophet, from Abraham onward, is not what he foresees. It is whom he can pray for, and whom God heals as a result.