Chabad.org — English translation + Rashi
Torah Temimah (Eruvin / R. Huna): “על פי ה׳ יחנו” is also brought to the measure of techum: residents of temporary huts measure only from the entrance of their houses.
English: Rav Huna said: those who dwell in temporary huts — one measures for them only from the entrance of their houses.
Techum measurement — the camp’s mobile, command-driven dwelling pattern supplies a model for how temporary residences are treated in the law of Shabbos boundaries.
Living under the cloud trains the nation in a form of residence that the Oral Law later uses to define the techum of transient dwellings.