"We wholeheartedly support the hands of soldiers and ministers to fight bravely and win God's battle with courage and wisdom," the letter in Hebrew said, according to Israel's Channel 14 television.
"From great brokenness and terrible pain, with God's help, we will rise up and grow strong. The nation of Israel will rise up bravely to attack its enemies, as King David of Israel said, 'I will pursue my enemies and destroy them, and I will not return until their work is finished.
Israel has been mercilessly bombarding the besieged Gaza Strip since October 7, after Palestinian factions launched an unprecedented offensive in southern Israel that killed 1,400 people and took at least 220 hostages.
According to the Palestinian Health Ministry, at least 8,805 people have been killed in Gaza since the start of the war, including 3,650 children and 2,252 women.
According to Israel's Channel 14, the rabbis also said that the public should be given advance warning and that the responsibility for civilian deaths lies with "the murderers who hide behind them."
A copy of the letter was posted on October 30 on the official Telegram account of right-wing Israeli journalist Amit Segal.
The publication of the letter came days after Israeli army spokesman Daniel Hagari claimed at a press conference that Hamas had "turned hospitals into command and control centers and hiding places for Hamas terrorists and commanders."
On Friday, Izzat al-Rashik, a Hamas political figure, denied allegations that the group was using al-Shifa hospital as a shield for its underground military infrastructure, Al Jazeera English service reported.
Who are these rabbis?
Among the signatories of the letter are right-wing rabbis known for their questionable views in the past.
"There is nothing wrong with killing innocent civilians and destroying Gaza"
One of the leading signatories of the letter, Dov Lior, is a right-wing rabbi and spiritual leader of the entire far-right Religious Zionism coalition, which includes Religious Zionism, Jewish Power and Noam. He is also the spiritual guide and ally of the far-right politician Itamar Ben-Gvir.
Lior has consistently supported the construction of illegal settlements on Palestinian land and does not recognize the right of Palestinians to own land.
From 1987 to 2014, Lior was the rabbi of Kiryat Arba, an illegal Israeli settlement in the occupied city of Hebron.
In 1994, one of his students, Baruch Goldstein, shot and killed 29 Palestinians at the Ibrahimi Mosque in Hebron. Lior later described Goldstein as "holier than all the martyrs of the Holocaust".
Lior also expressed written support for the 2011 book The King's Torah, a racist and genocidal book written by rabbis Yitzhak Shapira and Yosef Elitzur, which endorses the killing of non-Jewish babies deemed to pose a risk to Jews.
In July 2014, during Israel's previous invasion of the Gaza Strip, Lior issued a "psak halacha" (religious ruling) authorizing the destruction of the entire Gaza Strip and relieving Israeli soldiers of the obligation to distinguish between combatants and non-combatants. He also said it was permitted to block supplies or electricity, as Israel is currently doing in Gaza.
"It is okay to kill innocent civilians and destroy Gaza," Lior said.
In 2013, the Israeli newspaper Haaretz published an article stating that "if Rabbi Dov Lior were a Muslim, Israel would probably assassinate him."
Rabbi Zvi Yisrael Tau
Zvi Yisrael Tau, 86, is the head of the influential Har Hamor Yeshiva in Jerusalem and spiritual leader of the anti-LGBTQ Noam political party.
According to an article published by the Shalom Hartman Institute, a Jerusalem-based Jewish research and education institute, Tau has also said on the issue of Jewish sovereignty over the Land of Israel that Israel's attacks are "wars to establish our kingdom, to establish our strength and national courage."
According to the Times of Israel, Tau's name was embroiled in controversy last year when several women claimed that he had sexually assaulted them.
Rabbi Yitzhak Ginsburgh
Born in the United States in 1944, Yitzhak Ginsburgh made a name for himself in Israel as a leading authority on Jewish Torah and mysticism.
In 1994, the student of Dov Lior wrote a pamphlet praising Baruch Goldstein, an American doctor who murdered 29 Palestinians while they were performing dawn prayers at the Ibrahimi Mosque in Hebron during the holy month of Ramadan.
Goldstein was a member of Rabbi Meir Kahane's Kach party, declared "illegal" in Israel and designated a "terrorist organization" by the US State Department.
Kahane, who was killed by a gunman in New York in 1990, preached that only Jews should be able to live freely in Israel and encouraged violence against critics of the country.
Ginsburgh also endorsed and co-authored parts of The King's Torah with Yitzhak Shapira, a right-wing settler and rabbi.
The book purports to summarize the "legal contexts" in which Jews can kill non-Jews.
According to the Times of Israel, one section of the book permits the killing of non-Jewish babies "if they are likely to grow up to be like their evil parents."
The controversial rabbi sparked criticism in 2019 when Rafi Peretz, Israel's former education minister, and Bezalel Smotrich, now Israel's finance minister, agreed to speak at an awards ceremony celebrating the right-wing rabbi.
Rabbi Meir Mazuz
Known for his controversial views, Meir Mazuz is Israel's senior Sephardic Haredi rabbi, head of the Tunisian Jewish community and spiritual leader of the Shas Party. During a recent Shabbat conference, he praised Baruch Goldstein as the man who "averted a very great danger" by massacring 29 Palestinians worshipping in the Cave of the Patriarchs in Hebron in 1994, The Jerusalem Post quoted Israeli news outlet Walla as saying.
Referring to the Palestinians killed at the time, Mazuz said that the worshippers "hid axes, guns, knives under their prayer rugs. -but- thanks to this Jew, the danger was averted."