Exodus 23:14-19 "Three times thou shalt keep a feast unto me in the year. Thou shalt keep the feast of unleavened bread: (thou shalt eat unleavened bread seven days, as I commanded thee, in the time appointed of the month Abib; for in it thou camest out from Egypt: and none shall appear before me empty:) And the feast of harvest, the firstfruits of thy labours, which thou hast sown in the field: and the feast of ingathering, which is in the end of the year, when thou hast gathered in thy labours out of the field. Three times in the year all thy males shall appear before the Lord GOD. Thou shalt not offer the blood of my sacrifice with leavened bread; neither shall the fat of my sacrifice remain until the morning. The first of the firstfruits of thy land thou shalt bring into the house of the LORD thy God. Thou shalt not seethe a kid in his mother's milk."
The number three, like the number seven, holds a special significance in the scripture. Jonah was three days and three nights in the belly of the great fish. Jesus was three days and three nights in the tomb. Liberty was seen in these instances of three.
The LORD commanded that there be three feasts unto Him each year. These feasts represented the liberty that God had visited His people with. The feast of unleavened bread signified the deliverance of God’s people by His hand from the land of Egypt. They ate unto His glory according to His blessing, and no leavening was to be found in their dwellings.
The feast of harvest also testified to the delivering blessing of God. It was the offering of the first and best that He had granted unto His children. The feast of ingathering was a testimony that God had provided for them through another year. They were free from want by His mercy and grace.
Today, we rejoice in the liberty of feasting on the goodness and mercy of God. We know that our Redeemer came out of the tomb and is alive forever more. We must throughly remove the worldly concepts from our dwellings (hearts and minds) so that we might make acceptable (living) sacrifice unto Him which is our reasonable service. The praise and the glory that we give to Him does not increase Him in any way or make Him more God than He already is.
The praise we offer Him (like the firstfruits) first came from Him. We have nothing to offer Him that we have not first received from Him. Even though we offer praise and worship to Him, it is we who benefit from giving Him praise and worship. We “feast” unto the LORD because He alone has blessed us to be able to do so.