What does Matthew 26:30 mean?

The Passover meal always ended with the singing of the last part of what was called the Hallel, from Psalm 113–118 or perhaps Psalm 136. "Hallel" refers to the repeated word "hallelujah." As the acting head of the household, in this moment, Jesus, would have sung one line after another as the disciples responded by singing the word "hallelujah."

The Israelites had sung these promises from God, year after year, for centuries. Now the disciples were singing them together with the Lord Himself, one last time, before the great act of love which would bring so many of these promises into reality: "Oh give thanks to the Lord, for he is good; for his steadfast love endures forever!" (Psalm 118:29).

After concluding the meal with the hymn, the group got up from the table and walked back to their nighttime campsite at the Mount of Olives (Matthew 24:3). Judas had already gone (John 13:26–30). It was just Jesus and the 11 remaining disciples. They will end up at a place called the Garden of Gethsemane (Matthew 26:36).