(By Iver Larsen, Bible Translation Consultant, April 2022)
Most people in the Western world have misunderstood the Hebrew expression three days and three nights. The reason is that they make the fundamental mistake of interpreting the expression from a Western perspective instead of a Biblical and Hebrew perspective. We find a similar misunderstanding concerning the expressions the third day and three days after. Inclusive counting is used in Africa and the Middle East even today.
Let me illustrate it from 1 Samuel 30:1:
David and his men reached Ziklag on the third day (NIV).
Two days later David and his men arrived back at Ziklag. (GNB)
Because inclusive counting is used, you can either be literal and say “on the third day” as in Hebrew or translate into normal English and say “two days later.” If they started the journey on a Monday, that would be the first day, so Tuesday would be the second/next day and Wednesday the third day/two days later. This kind of inclusive counting is used throughout the Bible. The word “Pentecost” comes from the Greek word for 50, because that day is exactly 7 weeks or 49 days after Easter Sunday. Lev 23:15-16 gives the instruction:
From the day after the Sabbath, the day you brought the sheaf of the wave offering, count off seven full weeks. Count off fifty days up to the day after the seventh Sabbath. (NIV)
Since the first day is counted as day 1, the 50th day is 49 days later.
So, when Jesus says no less than three times that he will be resurrected on the third day after his death, it must mean two days later. Obviously, Jesus uses the Hebrew way of speaking about counting days instead of the Western way that most people think. Jesus died on a Friday and was resurrected on the third day, which is Sunday.
But Jesus also said that he would be in the grave three days and three nights. In a language and culture that uses inclusive counting of days, it is strictly speaking impossible to talk about three days and three nights. If the period in question starts on a Monday, the third day would be Wednesday. However, there are only two nights in this period. To get three nights, we would have to start on a Monday as the first day so that the first night is between Monday and Tuesday. The third night would then between Wednesday and Thursday. But that would be the fourth day. So, with inclusive counting of days, the intervening nights must necessarily be one less than the days. Why does the Bible then not say three days and two nights? The reason is that Hebrew enjoys parallel numbers and expressions. It sounds better to say three days and three nights or 40 days and 40 nights. These are idiomatic expressions that mean a certain number of days, inclusively counted, but including the nights in between. In most cases, they would simply say 3 days or 40 days, but especially if it is a period of fasting, then it is important to add the nights to show that the fasting was not only during daytime, but it included the nights. The following quote is from IsraelBibleCenter:
despite Scripture’s reference to Jonah being in the fish for three whole nights, the rabbis after Jesus still speak of “the third day of Jonah” alongside a reference to “the third day of the resurrection of the dead” (Genesis Rabbah 56:1). Thus, the rabbis employ some poetic license when they interpret Jonah, and Rabbi Jesus does the same.
This kind of expression is used in 1 Samuel 30:12: for he had not eaten any food or drunk any water for three days and three nights (NIV). Other examples:
Gen 7:4,12 I will send rain on the earth for forty days and forty nights (It would rain throughout for 40 days and the 39 nights in between.)
Exo 24:18 And he stayed on the mountain forty days and forty nights. (He stayed there even during the 39 nights).
Exo 34:28: Moses was there with the Lord forty days and forty nights without eating bread or drinking water.
Lev 8:35 You must stay at the entrance to the tent of meeting day and night for seven days. (This is a different construction with the same meaning. Stay for seven days, both day and night.) This would be clearer in English, such as it rained for forty days, both day and night.
Deut 9:9, 11, 18, 25 and 10:10 forty days and forty nights.
1 Kings 19:8 he travelled forty days and forty nights
Esther 4:16 Do not eat or drink for three days, night or day (A different construction with the same meaning. Three days including the two nights.)
Job 2:13 Then they sat on the ground with him for seven days and seven nights. (Seven days including the six nights.)
Jon 1:17 (2:1) Jonah was in the belly of the fish three days and three nights. (Three days and two nights in that period.)
As long as we understand this Hebrew way of speaking, there is no contradiction between Jesus rising on the third day and him being in the grave for three days and two nights. Of course, we need to remember that in Hebrew a portion of a day is counted as a day. So, the few hours on Friday from 3 p.m. to sunset was the first day. Saturday was the second day and Sunday the third day. But he also stayed there during the two nights in between.
 This link might work: https://weekly.israelbiblecenter.com/resurrection-third-day/?unapproved=72780&moderation-hash=3f00afee6c44881c1a906ecdbade1b64#comment-72780