The Haftorah for Parashat Toldot, comes from the prophet, Malachi (Malachi 1:1-2:7). Malachi was part of the Men of the great assembly, he was the last of the Prophets that were around at the start of the second Beit Hamikdash. His prophecies make up part of the book of the 'Trei Assar,' a book featuring prophecies by 12 different prophets. Many even say that Malachi was actually none other that Mordechai from the Purim Story (Megillah 15a).
As the Parshah describes the birth of Yaakov and Esav (Bereishit 25:24), we viewed two contrasting personalities that were developed, Yaakov the Torah scholar and Esav the mighty hunter. As becomes apparent from the Parashah, Esav disliked Yaakov. After Yaakov took the blessings from Esav, he wanted to kill Yaakov (Bereishit 27:41), which led to Yaakov having to go to find a wife in Lavan's territory. Yaakov had the twelve tribes descend from him whereas Edom became a mighty super power in the world till this very day.
There are comparisons in this weeks Haftorah to the Parshah, in the second verse the prophet asks a rhetorical question from G-d, 'is it not that Esav was a brother to Yaakov (Malachi 1:2)?' It is evidantly seen that Esav certainly did not behaving like a brother to Yaakov as he sought to kill him (Bereishit 27:41).
The Prophet exclaims 'but Esav I hated and I made his mountains a desolation (Malachi 1:3),' this sounds like a very strong statment, however all throughout his life, Esav lived in an evil state (Megillah 11), his descendants were also wicked, steeped in Idolatry, murder and bloodshed, it was the descendants of Esav who destroyed the Second Beit Hamikdash, the Romans.
The prophet states 'A son will honor his father (Malachi 1:6),' To Esav's full credit, he excelled in the Mitzvah of honoring his father, Yitzchak, as is eveident from the Parshah that he hunted food for his father. To Honor ones father is considered so great it is likened to the honor of Hashem (Kiddushin 30b). Due to this very great mitzvah, Esav was awarded a potent blessing by Yaakov (Bereishit 27:39-40).
The prophet continues his message by addressing the Kohanim, how they had scorned G-d's name, offering defiled sacrifices, lame and sick animals (Malachi 1:1-8). The Jews during the era of Malachi were guilty of Idolatry, which is considered one of the three cardinal sin's, in fact it was the descendants of Esav who were most guilty of Idol Worship, however the prophet states how bad it was that the Kohanim, being the Jews were guilty of this transgression.
In the Parshah, Yitzchak blesses Yaakov with the power of Tefillah, however when his voice would not be in prayer directed to G-d, the 'Hand of Esav' could prevail. So too in this Haftorah, Malachi states, 'Pray now if you please before G-d that he be gracious to us from your hand (Malachi 1:9),' This refers to how Blessing can come through the prayer of Israel and how without it, the Hand of Esav could rule over Israel.
After Malachi further chastisises the Jews for bring false sacrifices, Malachi warns the Jewish nation, 'if you will not listen and if you will not take to heart to render honor to my name, said the master of the legions, Hashem, I shall curse your blessings (Malachi 2:2).' This proves how vital it is for the Jewish nation to strive to keep to the 613 mitzvot, since Yaakov, one of the forfathers of the Jews, was giving a blessing to be passed on down to all his decendants, it was a blessing on condition that the Jewish nation would adhere to the mitzvot, however if they were to fail to do so, it would lead to destruction, as the key would be given to Esav to rule and potentially destroy!
The prophet describes how G-d gave his covenant to the tribe of 'Levi (Malachi 2:4),' the tribe who had Moshe and Aharon descend from. They were zelous in performing the mitzvot and not going off the path, as is evident from the episode of the Golden Calf (Shemot 32:4). We should take an example of Levi, how they feared G-d, and we should always try to fear and love G-d. This will be the best way the Jews could bring the blessing on to themselves along with prayer. In fact the Levites replaced the First born, with this elevated covenant, after the transgression of the golden calf. The prophet stresses this in the Haftorah, since Esav was very quick to sell his birthright for a Pot of Lentils (Bereishit 25:29-34), the prophet stresses how precious the covenant of the first born is to G-d!
The Haftorah is concluded, with the prophet stating how the Kohanim should safeguard the knowledge of the Torah and teach it throughout the generations. Also encouraging Prayer, is another strong piece of advice that Malachi offers them (Malachi 2:7). Malachi's last words state how the Kohanim are an agent to G-d, just as we see that they were responsible for the services in the Temple, especially the Kohen Gadol having the great responsibility of entering the Holy of Holies every Yom Kippur, carrying out an incence service, in beseeching G-d to atone the his nation's transgressions over the past year (Vayikra 16:16).