Possible meanings are 1) Jesus is talking about a literal measure and giving generously to others or 2) this is a metaphor in which Jesus speaks of "understanding" as if it were "measuring." (See: [[rc://en/ta/man/jit/figs-metaphor]])
This can be stated in active form. Alternate translation: "God will measure that amount for you, and he will add it to you" (See: [[rc://en/ta/man/jit/figs-activepassive]])