We have a tradition that the Resurrection of the Dead in Israel will proceed the Resurrection of the Dead of the rest of the world by a span of forty years.

Nonetheless, anyone who had passed away (and was buried) outside of Israel and has merely one family member (the type for whom one would have to sit shiva) who resides in Israel at the time of Mashiach - that Israeli relative has the power to revive all his relatives who were buried abroad.

This concept is founded upon the Talmud in Pesachim (68a), which states: "In the future the righteous ones will resurrect the dead". The Talmud derives that from the verses "Thus says G‑d, 'Yet have the elders of Jerusalem to return each holding their walking sticks'" (Zechariah 8:4) and from "I shall place my walking stick upon the lad and resurrect him" (Kings II 4 29).

The terms "righteous" and "elders" are associated with resurrection. This hints to us the idea that all those that live in Israel are called "righteous". This is also seen by the association in the verse "And your nation is completely righteous, they will forever inherit the land". (Isaiah 60:21) Yet the main power of the ability to perform the Resurrection lays in the hands of those who are called "elders", the Torah scholars, as is implied by the verse "And you shall respect the faces of the elders". Upon that verse the Talmud has explained that "an elder is one who has acquired wisdom" (Kiddushin 32b).