The passage teaches that the Land of Israel, like faith itself, has the power to transform those dwelling within it by consuming them into its holy essence, as food transforms into the body of the one who eats it, thereby purifying the inhabitant from sin and ensuring their place in the world to come.
וְזֶהוּ: אֶרֶץ אֹכֶלֶת יוֹשְׁבֶיהָ – כִּי אֶרֶץ הוּא בְּחִינַת אֱמוּנָה, כְּמוֹ שֶׁכָּתוּב (תהלים לז): שְׁכָן אֶרֶץ וּרְעֵה אֱמוּנָה. וְזֶהוּ: אֹכֶלֶת יוֹשְׁבֶיהָ – כִּי כְּשֶׁנִּכְנָס לָאָרֶץ, שֶׁהִיא בְּחִינַת אֱמוּנָה, נֶאֱכָל אֶצְלָהּ, הַיְנוּ שֶׁנִּתְהַפֵּךְ לְמַהוּתָהּ. הַיְנוּ כְּשֶׁדָּבוּק לְהַצַּדִּיק וּמַאֲמִין בּוֹ, שֶׁהוּא בְּחִינַת אֶרֶץ, נֶאֱכָל לְהַצַּדִּיק וְנִתְהַפֵּךְ לְמַהוּת הַצַּדִּיק מַמָּשׁ: וְכֵן אֶרֶץ יִשְׂרָאֵל בְּעַצְמָהּ, יֵשׁ לָהּ גַּם־כֵּן הַכֹּחַ הַזֶּה. וְעַל־כֵּן אָמְרוּ רַבּוֹתֵינוּ זִכְרוֹנָם לִבְרָכָה (כתובות קיא): כָּל הַיּוֹשֵׁב בְּאֶרֶץ־יִשְׂרָאֵל שָׁרוּי בְּלֹא עָווֹן שֶׁנֶּאֱמַר: הָעָם הַיּוֹשֵׁב בָּהּ נְשׂוּא עָוֹן; כִּי הִיא אֶרֶץ אוֹכֶלֶת יוֹשְׁבֶיהָ, שֶׁהַיּוֹשֵׁב שָׁם נֶאֱכָל אֶצְלָהּ, וְנִתְהַפֵּךְ לְמַהוּתָהּ הַקָּדוֹשׁ. וְעַל כֵּן אֲפִלּוּ הַמְהַלֵּךְ אַרְבַּע אַמּוֹת בְּאֶרֶץ־יִשְׂרָאֵל, מֻבְטָח לוֹ שֶׁהוּא בֶּן עוֹלָם הַבָּא, כְּמוֹ שֶׁאָמְרוּ רַבּוֹתֵינוּ זִכְרוֹנָם לִבְרָכָה שָׁם:
This is the meaning of: A land that consumes its inhabitants—“Land” corresponds to faith, as it is written (Psalms 37:3), “Dwell in the land and cultivate faith.” This is: consumes its inhabitants—For when one enters the land, which is the concept of faith, he is consumed by it—i.e., he is transformed into its substance. In other words, when he is attached to and believes in the tzaddik—who is the concept of “land”—he is consumed by the tzaddik and is literally transformed into the tzaddik’s substance. The Land of Israel itself likewise has this power. Our Sages therefore teach (Ketuvot 111a): Whoever dwells in the Land of Israel resides without iniquity, as in (Isaiah 33:24), “The nation that dwells therein will be forgiven its iniquity.” This is because it is “a land that consumes its inhabitants.” One who dwells there is consumed by it and is transformed into its holy substance. Therefore, someone who walks even only four cubits in the Land of Israel is guaranteed the World to Come, as our Sages taught (Ketuvot, ibid.).