Exodus 10:21-23 talks of 3 days of darkness.. granted it's in the past.. but God has done several things related to this... Jonah spent three days and three nights in the belly of a great fish after being swallowed... Ezra waited three days before inspecting and assessing the work done on the temple.... Jesus's transfiguration occurred three days after His teachings about his suffering, death, and resurrection... Jesus is crucified, buried, and remains in the tomb for three days...

Generally speaking, three days could represent a time of transition, completion, and God's redemptive power.

Exodus 10:21-23 talks of 3 days of darkness.. granted it's in the past.. but God has done several things related to this... Jonah spent three days and three nights in the belly of a great fish after being swallowed... Ezra laited three days before inspecting and assessing the work done on the temple.... Jesus's transfiguration occurred three days after His teachings about his suffering, death, and resurrection... Jesus is crucified, buried, and remains in the tomb for three days...

Generally speaking, three days could represent a time of transition, completion, and God's redemptive power.