Descendants of Sephardic Jews, he said, will be considered "children of Spain."
The term "Sephardic" literally means "Spanish" in Hebrew, but the label has come also to apply to one of the two main variants of Jewish religious practice. The other and globally dominant one being "Ashkenazic," which applies to Jews whose lineage, in recent times, is traced to northern and eastern Europe.
Because of mixing between the groups and other factors, there is no accepted figure for the global Sephardic population but reasonable estimates would range between a fifth and a third of the world's roughly 13 million Jews. Hundreds of thousands live in France and so already have an EU passport. But the largest community is in Israel, where almost half of the 6 million Jews are considered Sephardic.
It is not completely clear how much of a historical link Spain will require. Most of Israel's Sephardics hail from northern Africa and southern Europe, which were early ports of call after the expulsion from Spain, and so they may be able to easily show direct links. But other communities, from places like Iraq and Yemen, are considered Sephardic by religious practice yet may have trouble proving a connection to Spain.
Either way, interest is already running high.
Hundreds of Israelis claiming Sephardic ancestry have contacted the Spanish Embassy, begun researching their family histories and taken to the airwaves to discuss their newfound citizenship possibilities.
To some, the prospect of Spanish citizenship marks a significant dose of historic justice.
To others, it simply offers a European Union passport. That's a big deal in a country that is still technically at war with many of its neighbors and where prosperity is a relatively recent phenomenon.
Israel's per capita GDP of nearly $40,000 year is significantly higher than that of Spain which has been wracked by economic crisis in recent years and on a par with rich nations like France and Britain.
But the Sephardics in Israel, despite their large numbers, have yet to close the socio-economic gap with the European Jews who founded the country and control most levers of power. There has never been a Sephardic prime minister, and the Ashkenazi Jews still earn more on average and are overwhelmingly dominant in academia and other key areas.
"I want to live somewhere else, and if I can do it without too much of a fuss I will," said Maoz Mizrachi, a 25-year-old salesman whose father's family traces its roots to Spain. "It's tough for young people to get ahead here and this gives me the opportunity to try somewhere else."
The fact that Israel's economy is actually in better shape than Spain's didn't seem to concern him: "If I get it (Spanish citizenship), I'll be the happiest guy in the world," he said.
Leon Amiras, who heads an association of immigrants to Israel from Latin countries, said his phone hasn't stopped ringing since the news emerged. "People from every corner are interested, from professors to doctors, engineers to plumbers and bus drivers," he said. "Everyone is talking about this."
The reform will allow dual nationality, enabling the newly minted Spaniards to retain their previous citizenship. Such an arrangement would give Sephardic Jews the same dual nationality privilege Spain currently grants only to Latin Americans. Elsewhere in Europe, Germany offers citizenship to descendants of Jews forced to flee the Nazis. Israel itself, of course, offers automatic citizenship to Jews.
Previously, under a 1924 law, the government had discretionary powers to award Sephardic Jews nationality, but the new law is much more far-reaching: According to Ruiz-Gallardon, Spanish nationality to those who can prove ancestry will be a right the authorities must honor.
The nuts and bolts of the new law, the government says, will be relatively simple: Applicants need only have their ancestry certified by a rabbi in any country and the Spanish Federation of Jewish Communities. Genetic testing has not been mentioned as an option.
The greater the documentary evidence an applicant presents, the quicker the procedure will run, Ruiz-Gallardon said.
Applicants will have to provide details of their birth and family name or prove knowledge of Ladino, the Judeo-Spanish language considered to be the "Yiddish" of Sephardic Jews.
For centuries Sephardic Jews have maintained some of their gastronomic customs, an extensive oral tradition of popular Spanish novels, and in some cases spoken Ladino, which is close enough to Spanish that it enables communication with Spanish speakers anywhere. Further details on eligibility will be published after lawmakers approve the legislation.
Malcolm Hoenlein, the executive vice chairman of the Conference of Presidents of Major American Jewish Organizations, doubted that Spain will receive a flood of applications for citizenship. But he said key questions remain on how people will prove eligibility.
"I'm sure it could be a bureaucratic nightmare to determine who is eligible and who is not," he said during a visit this week to Madrid in which he met with Prime Minister Mariano Rajoy and King Juan Carlos.
Sergio Della Pergola, a Jewish demographer at Jerusalem's Hebrew University, said it was very hard to give an exact number of descendants due to intermarriage and conversion over the years. But it was definitely in the millions, he said, estimating that in Israel alone about 2.5 million people were descendants of exiled Sephardim.
Shmuel Refael of Bar Ilan University thought the number of those who would qualify if the language provision was enforced is much lower, with only about 250,000-300,000 people in Israel having some potential knowledge of Ladino.
"It's very hard to reconstruct a list of exiled Jews of Sefarad (Spain), even though we know historically where the Sephardic Jews went, to the Balkans and north Africa," he said. "It will be complex and complicated to say an exact number of exiled Sephardim in the world."
Because Israel has association agreements with the EU, Israelis can generally travel there with great ease already. But an EU passport enables residence and work in the entire 28-nation bloc, giving access to high-quality, subsidized education.
Given Israel's existential angst, many citizens have sought foreign passports in recent years for other reasons, too, namely as a back-up plan for times of trouble. Israel is surrounded by hostile forces in Lebanon, Syria and Gaza, and faces constant tensions with Iran as well.
Spain's move is perhaps surprising because it comes during wrenching economic times in which one out of two youths are unemployed, raising questions among some about whether the country can sustain more immigration. Yet there has not been an outcry, and Spaniards seem generally behind the plan.
"In those times it was also permitted to burn and behead people," said Inaki Galipiento, a Madrid restaurant owner. "What they have now approved corrects a historic atrocity, and that's fine."
Spain's King Ferdinand and Queen Isabella issued the Alhambra Decree, also known as the Edict of Expulsion in March 1492, banishing Jews as part of a ruthless policy to unite Spain under the banner of Catholicism. The edict accuses the Spanish Jews one of the great Jewish centers of learning from that era of trying "to steal faithful Christians from our holy Catholic faith ... and subvert them to their own wicked belief and conviction."
Hoenlein, the Jewish American leader, said the government's Feb. 7 decision followed key steps by Spain in recent decades to address its painful Jewish past.
There are other important milestones. One that is frequently cited is the 2011 statement by the leader of Spain's Balearic Islands condemning the slaughter of 37 Jews from Mallorca in 1691 during the Spanish inquisition. King Juan Carlos' visit to a Madrid synagogue in 1992 to recognize "injustices of the past" is another.
Ruiz-Gallardon, the justice minister, has his own personal link to the issue. His great-grandfather Jose Rojas Moreno was the Spanish ambassador to Romania during World War II and is credited with helping to prevent deportations of Jews to concentration camps.
His actions helped evacuate 65 Jews to Spain and he also gave protection to the goods and estates of 200 other Jews, according to the International Raoul Wallenberg Foundation, which conducts Holocaust research.
"What the government is saying," Hoenlein said, "is there was something that took place and we can't rectify history but we can make this gesture."