The L-rd instructed the Israelites to present an offering of the firstfruits of the grain harvest to the priest when they entered the Promised Land (Leviticus 23:10-13). It is the first sign of the earth's 'release' of its fruits after the winter fallow period symbolizing the 'resurrection' of the annual growing season. Traditionally, this day was celebrated on the day after the weekly Sabbath that fell during Passover.
"Speak to the children of Israel and say to them: 'When you come into the land which I give to you, and reap its harvest, then you shall bring a sheaf of the firstfruits of your harvest to the priest. He shall wave the sheaf before the L-rd, to be accepted on your behalf; on the day after the Sabbath the priest shall wave it.'"
Before they could enter the Promised Land, though, they had to escape from their imprisonment and be 'resurrected' from slavery. The third day of their journey prefigured Jesus' resurrection on the 17th of Nisan, on the third day following His crucifixion:
Jacob's son Joseph was a type of the Messiah. Joseph died in Egypt where he was embalmed according to Egyptian custom. Since Joseph was a ruler in Egypt, he was probably mummified (bound in burial cloths used for the process), his body never seeing decay just as Jesus' body did not see decay (Psalm 16:10, Acts 2:27, 30; 13:34, 37).
Joseph made his brothers promise that when G-d sent the Israelites back to Canaan, they would take his body with them. Therefore, when Pharaoh finally was forced to allow the Israelites to go into the wilderness to worship G-d (Exodus 3:18), the Israelites went directly to Succoth where Joseph was buried. They left Ra'meses on the 15th of Nisan on the three-day journey to Succoth arriving on the 17th of Nisan. It was then that Joseph's body was symbolically 'resurrected on the third day' from his grave, joining the Israelites escaping bondage in Egypt.
It was at Succoth that the Israelites were first protected by the Cloud of Glory by day and the Pillar of Fire by night, a type of the resurrected Jesus guiding them on their journey. G-d opened the Red Sea as the way of escape for the Israelites and the way of death for the Egyptians.
Long before the Exodus from Egypt, though, G-d prefigured Jesus' resurrection on the 17th of Nisan in the story of Noah and the Flood.
Genesis 8:4 states that Noah's Ark rested on Mt. Ararat on the 17th day of the seventh month, resurrected from its watery grave. Nisan was the seventh month in the days of Noah. [G-d changed Nisan to the first month during the Exodus from Egypt, see Exodus 12:2]. The Ark was opened as a way of escape for Noah and his family allowing them to escape the Flood which was G-d's vehicle of death for the world.
Jesus was freed from His grave clothes and resurrected on the 17th of Nisan. His resurrection pointed to the way of escape from eternal death that was opened to all who would put their trust in Him; but it signaled eternal death and destruction to Satan and all who follow him.
The evening immediately following Jesus' resurrection at the end of the 17th of Nisan began the Feast of Firstfruits. On that day, the priest was to wave a sheaf of new grain before the L-rd, to be accepted for them to insure good crops for the coming harvest. This was meant to point the Israelites to Jesus' resurrection from the earth. Concerning His impending death, Jesus said:
"Most assuredly, I say to you, unless a grain of wheat falls into the ground and dies, it remains alone; but if it dies, it produces much grain." (John 12:24)
After Jesus' resurrection, when He appeared to Mary Magdalene at His tomb on the Feast of Firstfruits, He told her not to touch Him because He had not yet presented Himself to His Father. He had to present Himself as the Firstfruits of the Resurrection in His Father's Temple in Heaven:
"Jesus saith unto her, 'Touch Me not; for I am not yet ascended to My Father: but go to My brethren, and say unto them, "I ascend unto My Father, and your Father; and to My G-d, and your G-d."'" (John 20:17)
The priest waving the grain offering before the L-rd symbolized Jesus being lifted up from the earth, ascending to the Father and being presented as the firstfruits wave offering before G-d's throne in Heaven to insure a good crop of believers in the coming harvest. Jesus then returned to present Himself to His disciples as the firstfruits of the resurrection of the dead (1 Corinthians 15:20).
The Jewish community today celebrates the Feast of Firstfruits according to the teaching of the Pharisees on the 16th of Nisan every year. However, the Saducees' interpretation of Leviticus 23:15 & 16 causes the date of the Feast of Firstfruits to 'float' based upon the date of Passover each year. The Saducees' method of interpretation results in the Feast of Firstfruits falling on the Sunday during Passover week every year, Resurrection Day. This agrees with the biblical prescription for computing the date. Most importantly, though, it agrees with the fact that Jesus was presented as the Firstfruits of the Resurrection on that day.