If in any four natural numbers, the difference between at least two of them is a multiple of 3. Why?

If in any four natural numbers, the difference between at least two of them is a multiple of 3. Why?

Because any natural number divided by 3, only 0, 1 and 2 can be left
If there are four natural numbers, the remainder must be repeated after dividing by 3. Subtracting the two repeated numbers is a multiple of 3

Some people say, "in any four natural numbers, the difference between at least two numbers is a multiple of three." is this sentence right? What do you think?

According to the stem analysis, for any four positive integers a, B, C, D divided by 3, there can be at most three different residues 0, 1, 2: (1) assuming that a, B, C residues are different, then the fourth number d divided by 3 can only be a residue of 0, 1, 2, so that it is the same as a residue of a, B, C (such as a), then D-A is a multiple of 3. (2) Let ABC have two numbers divided by 3 and the remainder is the same (let's say AB), then A-B is the multiple of 3. To sum up, for any four natural numbers, the difference between at least two numbers is the multiple of 3