1)
Does the Torah obligate to give a third of a Shekel each year for these matters?
1.
Rashi: The Torah obligates a half-Shekel each year for Korbanos Tzibur. They accepted an additional third of a Shekel for these matters.
2.
Malbim: The coinage changed (Melachim I, 7:26 1 ). Now, a third of a Shekel equaled what used to be half a Shekel. 2
1
And so Bava Basra 90a explains Yechezkel 45:12. (PF)
