These sections of the Tosefta provide: A) background on the years that preceded the destruction of the Second Temple, focusing on the violent behavior of the aristocratic priesthood; B) explanations for the destruction of the Second Temple, and C) hopes for (or confident assertions of) its imminent rebuilding.

Some of the hardships of this period are described in the passages that precede this tosefta (Menahot 13:18-20), which present additional examples of the violent conduct carried out by the priestly aristocracy against other priests and the general Jewish populace, as well as the violence of men of power toward fellow Jews during the years prior to the Great Revolt against Rome (66 CE). In that context, the Tosefta cites Abba Shaul ben Batnit and Abba Yose ben Yohanan who, according to rabbinic texts, lived in Jerusalem during the years that preceded the destruction of the Second Temple. This tradition (A) describes the violence and corruption of the priestly aristocracy in Jerusalem and their brutality toward other Jews (see also a parallel in Babylonian Talmud Pesahim 57a). Some of these priestly houses are also known from other rabbinic texts: for example, Ishmael ben Phiabi is mentioned in a positive light in Mishnah Sotah 9:15: “When Ishmael ben Phiabi died, the glory of the priesthood ceased to exist” (משמת ישמעאל בן פיאבי בטל זיו הכהונה). See also Tosefta Kippurim 1:21; Mishnah Parah 3:5; Tosefta Parah 3:6. Some of the leading families from the aristocratic priesthood that appear in Tosefta Menahot 13:21 are also mentioned by Josephus. Scholars link two passages from Jewish Antiquities to this text:

“About this time king Agrippa gave the high priesthood to Ismael, who was the son of Fabi. And now arose a [sic] sedition between the high priests and the principal men of the multitude of Jerusalem; each of which got them a company of the boldest sort of men, and of those that loved innovations about them, and became leaders to them; and when they struggled together, they did it by casting reproachful words against one another, and by throwing stones also. And there was nobody to reprove them; but these disorders were done after a licentious manner in the city, as if it had no government over it. And such was the impudence and boldness that had seized on the high priests, that they had the hardiness to send their servants into the threshing-floors, to take away those tithes that were due to the priests, insomuch that it so fell out that the poorest sort of the priests died for want. To this degree did the violence of the seditious prevail over all right and justice” [Jewish Antiquities 20.179-181; translation by William Whiston].

Cited from: http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.01.0146%3Abook%3D20%3Awhiston%20chapter%3D8%3Awhiston%20section%3D8

“He [Ananias the high priest] also had servants who were very wicked, who joined themselves to the boldest sort of the people, and went to the threshing-floors, and took away the tithes that belonged to the priests by violence, and did not refrain from beating such as would not give these tithes to them. So the other high priests acted in the like manner, as did those his servants, without any one being able to prohibit them; so that [some of the] priests, that of old were wont to be supported with those tithes, died for want of food.” [Jewish Antiquities 20.206-207; translation by William Whiston]

Cited from http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.01.0146%3Abook%3D20%3Awhiston%20chapter%3D9%3Awhiston%20section%3D2

The editor of the Tosefta placed the tradition attributed to Rabbi Yohanan ben Torta (B+C) after these descriptions of internal conflicts. Rather than aiming to provide explanations for the destruction, this text seems to use the destruction and its causes to support a didactic message against specific sins, especially within the Jewish community. Whereas this source acknowledges civil strife among Jews, it is silent on issues of Roman power and Jewish political activities against Rome. In fact, no mention of Rome appears in these teachings. Rabbi Yohanan ben Torta was active during the early second century CE in the Land of Israel (the province of Judea, known from Hadrian onward as Syria–Palaestina). In the Jerusalem Talmud (Taanit 4:6, 68d), he participates in an argument about Bar Kokhba, who led the final Jewish revolt against Rome (132-135 CE). This text follows the biblical pattern by presenting the destruction of the Second Temple and the resulting exile as punishment for Israel’s sins, also without reference to Rome. It compares the reasons for the Second Temple's demise to the catalysts for two earlier devastations: the destruction of Shiloh and of the First Temple in Jerusalem.

Shiloh was an early cultic center mentioned, for example, in Jeremiah: “Go now to my place that was in Shiloh, where I made my name dwell at first, and see what I did to it for the wickedness of my people Israel” (7:12, NRSV). According to this tosefta (B), its destruction is attributed to the disgraceful approach to sacrificial offerings that were held there.

The First Temple was destroyed on account of idolatry, forbidden sexual acts and the shedding of blood. These three sins are categorized in rabbinic texts as the most egregious offenses that can be committed. According to Jerusalem Talmud Shevuot 4:2, 35a, a Jew may violate any law in the Torah to avoid being killed, with the exception of these three transgressions (see also Jerusalem Talmud Sanhedrin 3:3, 21b; Babylonian Talmud, Sanhedrin 74a).

According to this tosefta, Rabbi Yohanan ben Torta asks why the Second Temple was destroyed. After all, this generation was known to “labor in the Torah,” meaning that they were committed to studying the Torah, and to tithe with utmost care. Interestingly, despite these virtues, this teaching describes exile as their punishment. This description is absent from a parallel teaching in the Jerusalem Talmud (Yoma 1:1, 38c). Thus, even though historical evidence demonstrates that the majority of this generation was not uprooted by force, as per biblical descriptions of the exile that followed the destruction of the First Temple, rabbinic texts defined Jewish existence after this destruction as a state of exile. This passage (B) concludes by stating that, according to Scripture, these three most severe sins are comparable to the love of mammon and hatred for one another, the two sins that seem to characterize Judean society prior to the revolt. That era was epitomized by a wide socio-economic gap among Jews as well as violence and strife.

The teaching in section (C) discusses the final Temple. It is unclear whether the words: “in our life and our days” should be read as a hopeful prayer or as a confident assertion that the Temple would be rebuilt in Rabbi Yohanan's generation. If this passage were indeed from the early second century–just before the Bar Kokhba revolt–it might confirm the views of scholars who claim that, in this period, there was a real belief that the Temple would soon be reconstructed (hopes for the rebuilding of the Temple in the near future can also be found in Tosefta Rosh HaShanah 2:9 and Tosefta Taanit 3:9).

Nevertheless, the decision to conclude this teaching with a vision of the future Temple suits its placement at the end of tractate Menahotin the Tosefta. The editors of the Mishnah and the Tosefta often ended tractates with an encouraging or hopeful passage. In this case, the Tosefta cites verses from Isaiah and Jeremiah that anticipate the final Temple in Jerusalem as a center for “many nations.” Here too, Rome is unmentioned, but numerous unspecified nations are foreseen coming to the Temple and accepting God’s rule.