Numbers are endless. You can keep counting forever and never reach the last one. The first two lines of this short poem capture that feeling: "Never ending" and "Repeat infinitely" make counting sound like a loop with no exit. Then the third line surprises us by claiming that "every number equals four."
That claim doesn't work as maths, and it seems to be the point. One reading is that the speaker is playing with a puzzle, since there is a well-known word game in which every number's letter count leads you to four. I'm inferring that from the line, not from anything the poem says outright. Another reading is that the claim shows how numbers can feel both limitless and strangely trapped, always pulling back to the same place.
The speaker sounds curious and a little amused, maybe slightly stuck. The mood is quiet and puzzling. Opening and closing on the single word "Numbers" makes the poem itself feel like a loop.