Rabbi Akiba was walking with his colleagues, Rabbi Gamaliel, Rabbi Eliezer, and Rabbi Joshua, on the Temple mount that was in ruins. All four rabbis saw a little fox run about on the ruins of the Temple mount, on the place where the Holy of Holies once stood. Three of the four began weeping, but Rabbi Akiba laughed. "Why do you weep?" Rabbi Akiba asked his colleagues. The three answered, "Because the place of the Temple is now the place of the fox." Then the three rabbis asked Rabbi Akiba, "Why do you laugh, seeing all the destruction, seeing that the people are gone and only the fox remains?" Rabbi Akiba answered, "Because just as the prophet foretold the destruction of Jerusalem, so the prophet foretold the future restoration of the city. Now that Jerusalem has been destroyed, the first prophecy fulfilled, we know that the second prophecy, the rebuilding of Jerusalem, will also be fulfilled."
Babylonian Talmud Makkot 24b