In this passage, Tobit tells of how he intended to invite one of his impoverished countrymen to eat with his family. When his son reported to him that there was a murdered Israelite in the street, Tobit “sprang up, left the dinner before even tasting it, and removed the body from the square.” Then he quotes Amos 8:10, not saying that it was fulfilled but that this particular event reminded him of Amos’ prophecy.
The author of this story, or this part of the story, set Tobit’s life from before 922 B.C. to after 722 B.C. Amos’ prophetic ministry ranged from 760 B.C. to 750 B.C. Whereas Isaiah would prophesy to Judah (the southern kingdom) concerning the exile of Judah into Babylon, Amos prophesied to Israel (the northern kingdom) concerning the exile of Israel into Assyria. Tobit is pictured as a resident of Israel (the northern kingdom). Just as Tobit is portrayed as living during the ministry of Isaiah, who followed Amos, he is also presented as living during the ministry of Amos in the territory where Amos was prophesying. It makes sense that Tobit would quote from Amos’ prophecy.
What the author of this part of Tobit’s story describes is exactly the type of thing that Amos prophesied concerning the exile during which the story of Tobit is set. From this, we see that in and following the 3rd Century B.C, the festivals were still highly prized, and it was important for the people to observe every festival, especially Pentecost (v. 1). We learn, here, that “Pentecost” was a term used to refer to the Old Testament Feast of Weeks (Exodus 23-24, Leviticus 16, Numbers 28, Deuteronomy 16). The term, “pentecost,” was used at least as early as the 3rd Century B.C. and was the most common term used to refer to the Feast of Weeks by the time we see it used in the New Testament (Acts 2). This is how we know that the New Testament Pentecost is the equivalent of the Old Testament Feast of Weeks. From the exile into Assyria until the coming of the Holy Spirit, the Feast of Weeks or Pentecost would be a time of mourning. The Feast of Weeks was essentially a harvest festival on which the Israelites would take a break from their labor and enjoy the first-fruits of their harvest. This is difficult to do as an exile or under Roman rule. The harvest would be sparse if there was a harvest at all. It is during Pentecost, by the coming of the Holy Spirit, God gleaned His first-fruits in Christ from the nation of Israel. So, this is what we celebrate as Christians. This is what the Feast of Weeks was meant to foreshadow. It was another presentation of God’s Gospel within the Law. This is the very truth that Amos prophesied in Amos 9:11-15.
So, the Law was highly prized, but the promise was not considered. Here, in Tobit, we see the Law of God elevated but an absence of God’s promise to deliver Israel. This tendency in the literature of the time reveals to us why the Pharisees and scribes may have been so hesitant to accept any Messiah. Human works were elevated above the promise of God to deliver His people.