Scripture tells us what our Savior did to acquire spiritual strength, in connection with the devil's attack on Him: "Then Jesus was led up by the Spirit into the wilderness to be tempted [or tried] by the devil. And when He had fasted forty days and forty nights, afterward He was hungry" (Matthew 4:1–2). Notice—He fasted!

Full text at - http://www.tomorrowsworld.org/commentary/by-prayer-and-fasting