My bible study group were looking at Matthew 4:1-11 about Jesus being tempted in the desert. We were wondering if it was a literal 40 days or if those 40 days might be a metaphor for Jesus' entire time on Earth? If so the desert might be a metaphor for this world, because it is as bleak and empty of spiritual nourishment as a real desert is void of food and water. If Jesus was fully human, he would have died after 40 literal days with no food or water, right?
First, proper interpretation of scripture depends on following certain rules (called hermeneutics) which guide a student into a proper view of the text. One of the rules of proper interpretation is the Golden Rule, which states that when the plain sense of scripture makes common sense, seek no other sense. Said another way, when the common, ordinary meaning of the text is sensible, then we have no justification to substitute a secondary or hidden meaning.
In the case of the account of Jesus’ 40-day fast in Matthew 4, the plain sense of the text says Jesus fasted for 40 days, and there is no justification to seek a secondary or alternative meaning to those words. The proper interpretation is that Jesus did, indeed, fast for 40 continuous days. You assumed Jesus drank no water during this time (which would render the meaning of the text nonsensical), but look carefully at what we’re told in Matthew 4:
Matt. 4:1 Then Jesus was led up by the Spirit into the wilderness to be tempted by the devil.
Matt. 4:2 And after He had fasted forty days and forty nights, He then became hungry.
Notice the text says Jesus fasted. It does not specify the type of fast He undertook. Furthermore, at the end of the fasting period Jesus is reported to have become hungry (but not thirsty). Finally, looking at Luke’s Gospel account of the same moment we find this:
Luke 4:1 Jesus, full of the Holy Spirit, returned from the Jordan and was led around by the Spirit in the wilderness
Luke 4:2 for forty days, being tempted by the devil. And He ate nothing during those days, and when they had ended, He became hungry.
Luke says specifically that Jesus "ate nothing" during the 40 days. From these careful observations we learn that Jesus fasted only from food, not from food and water. He was evidently drinking water throughout the 40 days. This is typical of Jewish fasting customs of the day. Jews will fast either from food alone or from food and drink. Food fasts may last up to forty days, while food and drink fasts last no more than seven days.
In both cases, a body can survive with no serious risks. In fact, 40-day food fasts are still practiced today among both Jews and Christians. Christians who have participated in 40-day fasts report that hunger pangs cease after 2-3 days and don't return again until around the 40th day, just as the Gospels report in Jesus’ case.