The sages of the Mishnah and Gemara (Talmud) had permission to legislate new rules in Judaism, as long as they didn't contradict existing Torah rules. The Almighty Himself granted this permission in the Torah. Eruv is a rabbinical law.
5 tourists rescued from Hebron after being hit by firebomb; 2 hurt (Haaretz)
from the article: Forging a golden age