Rashi on Deuteronomy 11:6/רש"י על דברים י״א:ו׳

1בקרב כל ישראל [AND THE EARTH SWALLOWED THEM UP] IN THE MIDST OF ALL ISRAEL — Wherever one of them fled the earth was riven beneath him and swallowed him up. This is the view of R. Judah. Rabbi Nehemiah said to him: But is it not already stated, (Numbers 16:32) “And the earth opened its mouth”, and it does not state “its mouths”? Whereupon he (R. Judah) asked him: “But how, then, can I explain the words: “in the midst of all Israel” (if there was but one spot at which they were swallowed up, as you suggest Scripture states by the word פיה, “its mouth”)? He replied to him: you can reconcile the two texts by assuming that the earth became a declivity, — something like a funnel, — and wherever it was that one of them happened to be, he rolled down until he reached the place where the fissure was (cf. Yalkut Shimoni on Torah 752).

2ואת כל היקום אשר ברגליהם AND ALL THE SUBSTANCE THAT WAS AT THEIR FEET — This means a man’s money, that places him on his feet (Sanhedrin 110a).