One-Sixtieth
דברים כו, ב : וְלָקַחְתָ מֵרֵאשִׁית כָל-פְרִׁ י הָאֲדָמָה אֲשֶׁר תָבִׁיא מֵאַרְ צְךָ אֲשֶׁר ה' אֱלֹקֶׁיךָ נֹתֵן לָךְ וְשַמְתָ בַטֶׁנֶׁא
Baal HaTurim notes that the Gematria of the word טנא is 60. The Rambam in hilchos Bikurim 2:15 writes that the Torah does not specify the amount required to be given for Bikurim. However, the Rabbis required a person to give 1/60th. For this reason the letter ס is absent from this passage about Bikurim.
Perhaps his intention is that since one is required by Rabbinical decree to give a sixtieth; the owner will be left with 59 parts, with one going to the Kohen, which is alluded in the word טנ( 59)א(1). Therefore we don't have the letter that equals 60 in this chapter. Also, the Torah uses the unusual word טנא (which appears 4 times in Tanach) and not the usual word סל (which appears 15 times in Tanach) for a basket.
Amen
דברים כז, כו: וְ אָמַר כָל -הָעָם אָמֵן
Baal HaTurim remarks that the gematria of the word אמן is 91 which is equivalent to that of the combined Names of 'Havayah' and Adnus' (the written and spoken special name of HaShem). Hence Chazal have said that someone who answers 'Amen' to a Berachah is greater than the person who recited the Berachah, since his declaration incorporates two Names of Hashem as against the one Name recited by the person who recites the Berachah.
Life in Balance
דברים כח, ס וְהָיוּ חַיֶיךָ תְ לֻאִים לְךָ מִנֶגֶד וּפָחַדְתָ לַיְ לָה וְיוֹמָם וְלֹא תַאֲמִין בְחַיֶיךָ
Baal HaTurim remarks that we find the word "tlu'im" one other place in Tanach, "V'ami tlu'im limshuvosi" (Hoshea 11:7). This alludes to the statement in the Gemara R.H. that "beinonim" have their judgment hanging between Rosh HaShana and Yom Kippur. This is "cha'yecho tlu'im" of our pasuk which depends upon personal repenting or not. This is "V'ami tlu'im limshuvosi," of the verse in Hoshea, which the nation is hanging depends upon if the entire nation does teshuvah.
The Divine Name
דברים כח, סח : וֶׁהֱשִׁיבְךָ ה '
Baal HaTurim remarks the special name of HaShem appears 26 times in the Tochechah (Admonition). This corresponds to the 26 times that this name appears in the daily Amidah (without the added blessing on heretics) to protect against the 26 Names in the Tochechah.
This seems to imply that the Divine Name both punishes and protects against punishment at the same time. Rather, to mitigate against the 676 words of admonition, the pasukim contain 26 times the Divine Name. Thus, the 26 times of the value of the Name (gematria 26) equals 676 to mitigate against the 676 works of admonition.