Medical News Today:
The LORD did a miracle for Moses, Deuteronomy 9:
BBC:As a general rule of thumb, a person can survive without water for about 3 days.
Wiki ten men survived without food for 46 to 73 days.The longest someone is known to have gone without water was in the case of Andreas Mihavecz, an 18-year-old Austrian bricklayer who was left locked in a police cell for 18 days in 1979 after the officers on duty forgot about him.
The LORD did a miracle for Moses, Deuteronomy 9:
9 When I went up on the mountain to receive the tablets of stone, the tablets of the covenant that the LORD had made with you, I stayed on the mountain forty days and forty nights; I ate no bread and drank no water.
And likely for Elijah, 1 Kings 19:18Then once again I fell prostrate before the Lord for forty days and forty nights; I ate no bread and drank no water, because of all the sin you had committed, doing what was evil in the Lord’s sight and so arousing his anger.
Jesus might have carried water with him, Matthew 4:7 the angel of the LORD came again a second time and touched him and said, “Arise and eat, for the journey is too great for you.” 8 And he arose and ate and drank, and went in the strength of that food [and drink] forty days and forty nights to Horeb, the mount of God.
Matthew didn't mention Jesus was thirsty or turning anything into water.1 Then Jesus was led up by the Spirit into the wilderness to be tempted by the devil. 2 And after fasting forty days and forty nights, he was hungry.