To understand the depth of Rabbi Akiva Eiger's explanation of the Ran's words, let's first present the words of the Gemara (Pesachim 4b): "By Torah law, nullification alone is sufficient." Rashi explains: "It is written 'tashbitu' (you shall remove), and it is not written 'tav'iru' (you shall burn), indicating that 'tashbitu' is an act of the heart." Tosafot comments on this: "Rashi explained that because it is written 'tashbitu' and not 'tav'iru', it implies that the removal is done in the heart."

Tosafot raises objections: "Rabbi Yitzchak finds this difficult, because 'tashbitu' means burning, not nullification. As we learn in the baraita, Rabbi Akiva says there is no need, as it says 'tashbitu', and we find that burning is a primary labor (on Shabbat). Additionally, 'tashbitu' is explained later as applying from the sixth hour and onward, and after the prohibition begins, nullification is ineffective. Rabbi Yitzchak explains that by Torah law, nullification alone is sufficient because once nullified, it is considered ownerless and leaves his possession, making it permitted, as we say, 'But you may see the chametz of others and of the Temple.' And what we say in Nedarim (45a) that ownerlessness must be declared before three people, by Torah law, this is not required."

It is explained that according to Rashi and Targum Onkelos, the mitzvah of 'tashbitu' depends on the intention of the heart. According to Tosafot, it depends, according to Rabbi Yehuda, on the act of burning, and according to the Sages, also on crumbling and scattering to the wind. Nullification is effective by making it ownerless. Clarification is needed for Rashi's view, which seems to imply from the words of the Tannaim that burning depends on an action, in line with Tosafot's view, not on the intention of the heart.

We have already presented the Ran's resolution of Rashi's view, that 'tashbitu' can be fulfilled in two ways: through the intention of the heart or through actual burning, and he brought a source from the Gemara for both ways.