These rhetorical questions anticipate a negative answer and emphasize that only Yahweh is able to do these things. Alternate translation: "No one but Yahweh has measured ... and the hills in a balance." (See: [[rc://en/ta/man/jit/figs-rquestion]])
A "span" is the measure of length between the thumb and little finger when the hand is outstretched. Yahweh knowing the length of the sky is spoken of as if he measured it with his hand. (See: [[rc://en/ta/man/jit/figs-metaphor]])