On the night before Jesus was crucified, he said to his disciples, “A new commandment I give to you, that you love one another: just as I have loved you, you also are to love one another. By this all people will know that you are my disciples, if you have love for one another.” (John 13:34–35 ESV).
On Maundy Thursday, Christians remember this new commandment to love one another (or, in Latin, mandatum). We eat together and fellowship together. Then, we end with the Lord's Supper as we approach Good Friday.