Q. Where in the Bible does it say Moses was up the mountain 40 days (I thought it did but cannot find it) The thing I am trying to figure out is that Pentecost is 50 (or 49) from the Passover (?) and signifies when Moses went UP the mountain. So if the Passover is on the last night they were in Egypt and Moses going up Mount Sinai refers to Pentecost – How come it was 3 months (90 days) EX 19:1 – to the very day that they arrived at Mount Sinai and not 50 (49) days ? How does that all tie in?
A. Passover was the last day the Israelites were in Egypt. According to Exodus 12:1 Nisan had just become the first month, and Passover was in the middle of it, on the 14th day. So 2 weeks after they left, the 2nd month began, and after that came the 3rd month. Exodus 19:1 says they arrived at the Sinai Desert in the 3rd month on the very day, which means the day the 3rd month began, and camped before the Mountain. Pentecost commemorates the day they received the Law and it’s on the 6th day of the 3rd month. It’s 49 days after First fruits which is the Sunday after Passover. So on the sixth day after they arrived at Mt. Sinai they received the Law from the mouth of the Lord (Exodus 20:1). The 40 day period Moses spent on the Mountain began shortly afterward (Exodus 24:18) and at the end of it he returned with the stone tablets (Exodus 31:18).