יחזקאל, פרק מ״ז, פסוק ד׳

The prophet's journey continues down the flowing stream, revealing a steady, gradual increase in the water's depth at each measured interval. Following the course of the riverbed for an additional thousand cubits, the prophet is led directly through the water, which has now risen to cover his legs up to the knees [מלבי״ם, ביאור שטיינזלץ, מצודת דוד, מצודת ציון, רד״ק].

A third span of a thousand cubits is then measured [מלבי״ם], and the water swells further until it reaches waist height [מצודת דוד, מצודת ציון, ביאור שטיינזלץ]. This depth marks a critical turning point in the journey. Beyond this location, the river becomes overwhelmingly deep and impassable. Recognizing the growing danger, the prophet steps out of the stream, standing safely on the dry riverbank to measure the next segment. From this natural progression, a practical law is derived regarding personal safety: a person is forbidden to wade into a body of water that rises above their waist, out of concern that the current might sweep them away and endanger their life [רש״י].