Many of the sayings of Jesus are so famous that we hardly need to reference Him as the source.
Matthew 25:40, “Whatever you do for the least of these, you do for Me.”
Mother Teresa used to condense the saying into just five words. Many told the story of how she would grab hold of their hand, spread out their fingers and one by one and number each with a single word,
It is not just a useful visual aid, it is the truth: our works of mercy are not just good deeds for yet another person in need.
They are in service of a holy and deserving Person.