Israel is 8,000 square miles.
From the North to the South, the country is 263 miles long. A fighter jet can fly from the Lebanon border (in the North) to Eliat (in the South) in 11.5 minutes.
Stretching from East to West, at it's narrowest point Israel is only 9 miles across, while at it's widest point it is 71 miles across. You could walk (yes... "walk") from the West Bank to the Mediterranean Sea in 2 1/2 hours.
To visualize how small Israel is - it is just a bit bigger than the state of New Jersey. To really get a good idea of how small Israel really is, I find it is best to compare it to other countries.