Rabbi Yitzhak Kaduri has been released from hospital in Jerusalem, after feeling unwell earlier.
Earlier, Rabbi Kaduri was taken to the Bikur Holim hospital in Jerusalem after suffering from weakness. He underwent a series of medical tests, before receiving treatment.
Friends of the rabbi say he has been suffering from severe flu. "We and his family are praying for his welfare," said a friend. Rabbi Kaduri is over 100 years-old.
Kaduri started out as a modest bookbinder, and has become one of the best known Kabbalists in the country.
He was born in Iraq, and immigrated to Israel at the age of 17. He studied in a Jerusalem Yeshiva, and was a student of Jerusalem Kabbalists who worked in the capital at the start of the previous century, including Rabbi Eliyahu, father of Rabbi Mordechai Eliyahu.
Kaduri is considered a world Kabbalah expert.
Popular spiritual leader
Many members of the public possess a gold or silver mascot made for them by Kaduri. He has publicly backed the Shas party, and the humble Rabbi was introduced to the party by Aryeh Deri.
In recent months, Kaduri offered a blessing to opponents of the disengagement from Gaza, but surprised many followers when he offered his support for Prime Minister Ariel Sharon's Gaza pullout in April.
"If we give them a small thing and there will peace with them, we can leave Gush Katif. We can trust Sharon, he is okay. It is allowed to give up on territories in Gaza," the Rabbi told an ultra-Orthodox newspaper.
He added: "I have no faith in the Arabs but we must have a little quiet. Sharon's government isn't so bad.
Recently, rumors have circulated in the ultra-Orthodox world that that the messiah has revealed himself to Rabbi Kaduri in dreams.
Ilan Marciano contributed to this report