Thank you my dear friend for such an excellent question! Well, first of all, most Bible scholars consider this chapter to be more of a prophetic word from the Holy Spirit through Jacob declaring the future history of these tribes. This, I believe, is outlined for us in verse 1 of chapter 49 where we read: “And Jacob called unto his sons, and said, Gather yourselves together, that I may tell you that which shall befall you in the last days”. It appears to me that the sons of Jacob were held accountable for their actions, and that these actions, at least in part, impacted the nature of blessings being conferred on the various sons. And yet, some of the tribes, by God’s sovereign will, would have a more or less honorable place among the tribes, and indeed might experience greater or lesser “blessing,” despite birth order, and even in view of some of their failures. Consider the fourth son (Judah) in verses 8-10. It appears to me that despite the complicit acts of Judah in helping his brothers to sell Joseph into slavery, his family would have that special honor of bearing the line of David up to the Great King, the Christ, who will one day sit upon David’s throne. Other sons of Jacob (specifically Reuben, Simeon, and Levi), who were higher up in the birth order, had their shortcomings identified and were denied some of the honor that others received, apparently according to their character. Do remember, however, that the 12 tribes are seen by God as a whole people, and are yet the “apple of God’s eye” (Deuteronomy 32:9-10); and in the latter days, when the Lord Jesus Christ returns to Jerusalem after the Great tribulation, all the faithful remnant of Israel, representing all 12 tribes, will be brought back into the land and be abundantly blessed in the millennial reign of Christ Jesus, the Great King.  

But now, going back to Reuben, the first born, please note that in Bible times, the first son would generally receive a double portion of any inheritance, so thus the birthright should have fallen to Reuben as Jacob’s first born. However, in verses 3-4 we read that Reuben sinned with his father’s concubine (see Genesis 35:22), and this resulted in Jacob, through the Spirit of God, giving the birthright to his 11th son, Joseph. And Joseph appeared to be the godliest of all the brothers. Indeed, Joseph in many ways appears to be a “type” of Christ in that he was rejected by his own, falsely accused, went “down” into the pit (like death), but eventually rose up in power and saved his people Israel (by bringing them to Egypt and sustaining and caring for them there). On the other hand, Simeon and Levi demonstrated fierce anger and violence when they avenged their sister Dinah’s shame by killing every male in a nearby city where the perpetrator of the crime and his father dwelt (see Genesis 34:1-26. This act was strongly condemned by Jacob in his “blessings”, and yet, we find later that Levi would be the family of the Levitical priests (up to Christ).  

Now, for a very clear summary of the “blessings” of two of these sons and the future of the associated tribes, I’d like to quote a few lines from the MacDonald Commentary which I believe will help to shed more light on this subject: “Judah (meaning praise) would be praised and respected by his brothers because of his victories over his enemies. He is likened to a lion that goes forth to capture prey, then returns to well-deserved rest that no one dares disturb. Just as Joseph inherited the birthright with regard to territory, so Judah inherited it with regard to government. Rulership would continue in this tribe till Shiloh (the Messiah) came, and in Him it would remain forever. His people would give Him willing obedience in the day of His power…. Compassing the territories of Ephraim and Manasseh, Joseph is a fruitful bough, sending out blessing far beyond his own borders. He was the object of bitter hostility, but he did not yield, because he was strengthened by the Mighty God of Jacob-the One from whom the Shepherd, the Stone of Israel (that is, the Messiah) comes forth. God blesses Joseph with rain in abundance, wells and gushing springs, and numerous progeny…”.

Does this all seem a bit confusing? Well, the bottom line is that God is a God of Grace, and He also is sovereign in His purposes. I believe that what we have in Genesis 49 in the “blessings” of Jacob is more of a prophesy of the coming history of the 12 tribes of Israel, with at least a part of the explanation for the varying degrees of blessing and honor based not on birth order, but rather, based in part on the character and acts of the fathers of these tribes, and yet all within God’s Grace and His sovereign will. This is the same God who chose Jacob over Esau, and who brought unworthy persons like Rahab and Ruth into the very line of the Christ. God is sovereign, and His purposes are sure. And yet, God’s purpose for His people is always for their ultimate blessing. You and I, as born again Christians, have been brought into blessing by Christ Jesus through faith alone, and we are adopted as sons and made to be God’s people, though we were not His people before Christ, and though we were totally unworthy of such Grace due to our sins. But praise God for His amazing Grace through the Lord Jesus Christ! Likewise, God will one day bring the faithful of His people Israel into great blessing through Christ Jesus when He returns in power. “For I know the thoughts that I think toward you, saith the LORD, thoughts of peace, and not of evil, to give you an expected end,” (Jeremiah 29:11).  (SF)  (504.5)