Tosefta su Deuteronomio 26:78

We do not bring Bikkurim (first fruits) before Shavuot, and if they are [nonetheless] brought, we must wait until Shavuot arrives and [only then] recite the declaration [beginning with "My father was a wandering Aramean..." (Deut. 26:5-10)].

There is a stringency with Terumah and second tithe that there is not with first fruits: That Terumah and second tithe apply to [the lands of] Ammon and Moab, which is not the case with first fruits. There is a stringency with second tithe and first fruits that there is not with Terumah: That second tithe and first fruits require one to come to the "place" (i.e., the Temple, the "place" that God has chosen to have his name dwell (see Deut. 14:23 (second tithe), Deut. 26:2 (first fruits)), and they require a confession, and they are forbidden to a mourner -- but Rabbi Shimon permits them [to a mourner]. And they are liable in [the laws of] bi'ur (i.e., the requirement that one uproot produce growing during the sabbatical year, and declare it ownerless (see Sheviit 7:1, 9:4).]. Rabbi Shimon says, first fruits are exempt from bi'ur (Bikkurim 2:2). Rabbi Yosei says, since second tithe requires confession and first fruits require confession, [you must say that] since second tithe requires removal, so too first fruits must require removal as well. Rabbi Shimon said to him, since with second tithe, in which the requirement of bi'ur applies [both to seventh-year produce] as well as to money [exchanged for such produce], you must say that with respect to first fruits, as to which the money exchanged for them does not require bi'ur, [the first fruits themselves do not require removal during the sabbatical year].

Rebbi Meir says, “From where [do we know] that just like you have to bless [God] for good [things that happen to you], so too you have to bless [God] for bad [things that happen to you]? The Torah teaches us, ‘… that which Hashem, your God, has given you …’ (Deuteronomy 26:11). “Your God” [meaning] “your Judge”. For every judgment that He judges you, whether positively or negatively.”