It is common that a negotiated deal comes before the public for approval only if it was approved by a body representing that public. So it appears that Eldar's comment is useless. But he still contributes something. If the Knesset approves the deal, then according to Israeli customs, this approval should work. If one wants to legislate an appeal on Knesset decisions, it may need to be enshrined in a Basic Law, otherwise the appeal may appear unconstitutional. (Strangely, Basic Law: The Knesset does not specify the functions of the Knesset, these are only customary.) It is not clear to me why the authors of the bill did not place it as an amendment to a Basic law. The Supreme Court may declare it "unconstitutional", based on customs. But who knows.
Ex-FM Lieberman: Firebomb attack in Jerusalem a reminder that norm is Arab terror against Jews (Haar
from the article: Akiva Eldar / Referendum bill uses public as peace deal rubber stamp