The Hebrew cardinal number khamishim means fifty. While primarily a counting word, it appears in theologically significant contexts — most notably in the institution of the Jubilee Year and the dimensions of the tabernacle.
Fifty is the number of Jubilee. Leviticus 25:10 commands: 'Consecrate the fiftieth year and proclaim liberty throughout the land to all its inhabitants.' The Jubilee occurred after seven cycles of seven years — the 50th year was the year of release, when debts were cancelled, slaves were freed, and ancestral lands were returned. This institution embodied Israel's understanding that the land belongs to God (v. 23) and that no one could be permanently enslaved. The 50-day counting of the Omer from Passover to Pentecost (Shavuot) is another theological use of fifty — Pentecost literally means '50th day.' The tabernacle's outer court measured 50 cubits on two sides (Exodus 27:12–13). In the New Testament, the descent of the Holy Spirit at Pentecost — the 50th day after the resurrection — permanently fulfills and transforms both the harvest celebration and the Jubilee hope.