I used to sing "This is the day that the Lord hath made; let us rejoice and be glad in it!" every morning with my family to start our day. In my Bible studies, I have often looked up to see what "day" means when that word is used, but this particular instance of "day" somehow escaped my attention (habit, I suppose!). So, what day is it, really? Is it talking about the newness of each day that the Lord gives us to live for Him? I suppose it does not hurt anything to have that attitude toward each day, but let's take a quick look at the context of this verse.
As Christians who celebrate the feasts the Lord gave us, we recently celebrated, and studied, Passover. Most Christians know that at the end of the Passover supper Jesus had with his disciples, it is recorded that they sang a hymn and then went out. Wouldn't you love to know what hymn that was? Well, Jews by nature seem to be creatures of tradition (Fiddler on the Roof was quite accurate in that respect!). Jewish tradition often goes back to its biblical roots. Now, granted, there are many jewish traditions that God did not institute, such as keeping kosher, but we do find many "traditions" that even Jesus kept. One of these traditions would have been the hymn sung at the end of Passover. That same hymn has probably been sung since the time of David, and is still sung in Jewish homes all over the world today at the close of the Passover.
Have I kept you in suspense long enough? What hymn is it? It is called "The Hallel" or "The Great Hallel," and is actually Psalm 113-118. Yes, they sing the whole thing even today! Here is one passage from the Hallel:
Psalm 118:22 The stone which the builders rejected
Has become the chief cornerstone.
23 This was the LORD’s doing;
It is marvelous in our eyes.
24 This is the day the LORD has made;
We will rejoice and be glad in it.
25 Save now, I pray, O LORD;
O LORD, I pray, send now prosperity.
26 Blessed is he who comes in the name of the LORD!
We have blessed you from the house of the LORD.
This is obviously a messianic psalm, talking about the coming Messiah who would be rejected, which Jesus fulfilled. The main thing we want to look at here, though, is the "day." This is the song that Jesus sang after the Passover supper. Jewish days start at sundown the evening before, so it was actually the day Jesus died, and here Jesus is singing the psalm, the hymn, the song, that is sung on EVERY Passover, "This is the DAY the Lord has made; we will rejoice and be glad in it!" Did you realize that Jesus was rejoicing as He went to His death on the cross to be the Passover lamb, the lamb of God that takes away the sin of the world?
The Jews use a Haggadah, an official order of service, for the Passover, which all Jews use. It is interesting to note that this verse of the Hallel is the only one that is mentioned twice. Just a side note for now!
To understand more about God's purpose for Passover, try reading the Hallel. It was all fulfilled in Christ!