Verse 29 already taught Iruy. Why is it repeated here?
Moshav Zekenim, citing Rashi (Yuma 74b): Just like "Shabason" includes tasks that are not full Melachah, it is written together with Iruy to forbid afflictions other than eating and drinking.
Why is Yom Kipur called "Shabbos Shabason"?
Refer to 16:31:151:1.
Pirkei d'R. Eliezer (46): "Shabbos" is in this world. Shabason is in the world to come. The other Mo'adim will be Batel, but Yom Kipur will not be. 1
Aderes Eliyahu: This teaches that it is forbidden even in Melachah of Ochel Nefesh, unlike other Yomim Tovim.
Moshav Zekenim: Also Shabbos is called Shabbos Shabason (Shemos 31:15)! This is because [the world to come] is called 'the day that is totally Shabbos' (Tamid 7:4).
