Exodus 19:21

העד בעם signifies, WARN THEM not to ascend the mountain. פן יהרסו lit., LEST THEY BREAK DOWN — warn them that they shall not break down their post because that their longing is אל ה׳ TO THE LORD לראות TO SEE Him and they therefore would approach nearer towards the mountain, ונפל ממנו רב AND MANY OF THEM FALL — whatever of them it may be that falls, even though it be a single person only, will be regarded by Me as רב, many (cf. Mekhilta). פן יהרסו — The term הרס, “breaking down”, always denotes the separation of the collection of parts that constitute the edifice. Similarly those who depart from the position which people have taken up break down that position.

וַיֹּ֤אמֶר יְהֹוָה֙ אֶל־מֹשֶׁ֔ה רֵ֖ד הָעֵ֣ד בָּעָ֑ם פֶּן־יֶהֶרְס֤וּ אֶל־יְהֹוָה֙ לִרְא֔וֹת וְנָפַ֥ל מִמֶּ֖נּוּ רָֽב׃

And the Lord said to Moshe, Go down, charge the people, lest they break through to the Lord to gaze, and many of them perish.