Although many comments on this were deleted, the claim that Smotrich's claim is 'credible' hinges on ignoring much else he said. Or that the 'full' offer extends to Palestinians who can never return let alone be accepted as Israeli citizens. As for the Q, I don't find it terribly relevant since few Jews want to live in a Palestinian state, when they have other choices that aren't likely to be invalidated anytime soon. So the Q is interesting at a rhetorical/hypocrisy level at best.
Off the top of my head, a number of the communist-inspired Palestinian factions perhaps adopted a USSR version of rights. Broad on paper or in theory... (Wiki claims the PFLP was the 'second largest' group besides Fatah at one point.)
Purely at propaganda/rhetoric level, it doesn't take a lot find some statements paralleling Smotrich's, at least in times past. E.g.:
In spring 1969, one of the most prominent leaders of Fatah, Salah Khalaf (Abu Iyad), emphasized the humanitarian and non-racist nature of the Palestinian revolution “by clarifying our humane attitude toward Jews as people … and persuading them that we are not really as Zionism portrays us—savages who want to massacre them and throw their women and children into the sea.” He called on Arab states to say they were willing to receive all Jews who had migrated to Palestine from Arab countries and to restore their property and their civil rights as Arab citizens in those countries on an equal footing with other Arab citizens. He said Arab states should take advantage of the contradictions within Israeli society, especially between Oriental Jews and Western Jews.
Fatah's adoption of this objective provoked rich debate in Palestinian circles, with the Popular Front for the Liberation of Palestine (PFLP) and the Democratic Front for the Liberation of Palestine
Popular Democratic Front for the Liberation of Palestine (DFLP) taking distinctive positions. In the second half of 1968, the PFLP adopted the aim of setting up “a democratic Arab state on the land of Palestine, in which the cultural and religious rights of the non-Arab communities would be preserved, including the Jewish community.” That would come about after the destruction of Israel “as an economic, political and military entity based on aggression” and the liberation of Palestine. In 1970 the front judged that the long and arduous process of liberating Palestine would be achieved by “a broad-based, socialist, progressive national liberation movement, with a base much broader than the masses of the Palestinian Arab people,” and that the state that would be set up after liberation would be “defined geographically, not by the borders of Palestine as drawn by the British Mandate, but by the borders of the socialist, progressive popular struggle movement that achieves liberation.” It said that “within this state a democratic solution to the Jewish question will be possible, and the Jews will become citizens of that state with rights equal to those of other citizens, and with the same obligations.”
The smaller DFLP (mentioned above) had a similarly generous platform, on paper, of:
“[...] setting up a popular democratic Palestinian state in which Arabs and Jews could live without discrimination, a state opposed to all forms of class oppression, with all Arabs and Jews given the right to develop their own national cultures.” The front advocated addressing Israeli public opinion, opening a dialogue with all “progressive” Jews in Israel and the rest of the world, inviting them to “take part in the Palestinian national liberation movement” and to “join Palestinians in a common fight to liberate Palestine and establish a democratic state.” The front did in fact embark on dialogue with Matzpen , a small Israeli leftist organization with Trotskyite leanings, which favored the idea of setting up a binational state in Palestine.
N.B. the same source discusses that the [larger] PLO was (even on paper) much more ambiguous about the nature of the state it sought established.
FWTW, the 1988 PLO/PNC 'Declaration of Independence', while not mentioning Jews specifically, says that
the future Palestinian state should be 'free of ethnic, religius, racial discrimination' and does not elaborate on the question of religious affiliation or the role of Islamic law in a future Palestinian state.
Full text translated to English here on the UN site, with a translation corrigendum as well. OTOH one has to keep in mind that the same document says that '[t]he State of Palestine shall be an Arab State'. But that's in a sense part of the original sin of the "adoption of General Assembly resolution 181 (II) of 1947, which partitioned Palestine into an Arab and a Jewish State", in the view of the PLO (authors of that declaration). The same document finds it necessary to use phrases like 'Palestinian Arab people' (repeatedly) to make the distinction whose independence they are declaring.
TBH, I'm not sure why the first source I found is eliding some earlier Fatah declarations of a similar nature, because these also exist:
One of the strengths of Fatah and PLO was the secular message. Fatah’s ‘Seven
Points’, passed by the Central Committee of Fatah in January 1969, points to the
role of the struggle in the fight for an independent and democratic state: ‘Fatah,
the Palestinian National Liberation Movement, solemnly proclaims that the final
objective of its struggle is the restoration of the independent, democratic State of
Palestine, all of whose citizens will enjoy equal rights irrespective of their religion’ (Fatah 1969: Article 5). The vision of the future Palestinian state, as stated
above in Article 5, was a democratic state embracing the freedom of religion. In
an interview in August 1969, Yasir Arafat defines the aim of the struggle in
similar terms: ‘. . . an independent, progressive, democratic State in Palestine,
which guarantees equal rights to all its citizens, regardless of race or religion’
(Arafat 1969: 136).
But then there's the realpolitik angle that gave the Fatah/PLO the broadest support by not talking about that equality much, let alone [about] secularism...
In 1968, Salah Khalaf (Abu Iyad) suggested the formulation of the ultimate
goal of the Palestinian struggle being ‘a democratic and secular state’. His idea
was rejected by the Fatah mainstream and the PLO, since it implied equality for
Jews, a contested issue within the ranks of PLO (Kimmerling and Migdal 2003:
317). By focusing on the struggle for independence and leaving the question of
religion aside, the leadership avoided an internal division along the religious/secular, as well as Muslim/Christian, cleavages. Instead, the national narrative
allowed for Yasir Arafat and the Palestinian leadership to gain widespread
support from large and diverse sections of the Palestinian population, including
traditional elites, conservative Islamists and radical left-wingers. Also, the leftist
fraction, PFLP and DFLP, for whom the struggle for Palestine was first and foremost a class struggle, accepted Arafat’s version of the national struggle (Lindholm Schulz 1999: 32–3, 121–5; Sayigh 1997).
And then, despite PLO's attempt to be ambiguous about this, Hamas and the Islamic Jihad directly charged it with the fatal sin of aiming for a secular state, e.g. in the 1988 Covenant of Hamas Hamas, article 27.
If you somehow need more similar quotes from other speeches (similar to the 'Declaration of Independence'):
In his speech upon his return to Gaza on 1 July 1994, Arafat stated: ‘We want to build our homeland as free men, a homeland of democracy, freedom and equality’ (Arafat, quoted in Sosebee 1994: 19).
(Same source/book -- Political Leadership, Nascent Statehood and Democracy: A comparative study by Möller & Schierenbeck, 2014)
FWTW, the PLO & Fatah advertised the membership of a few Jews or at least 'person[s] of Jewish origin' to use The Guardian's wording in their ranks. They seem to be too few for any official demographic statistics though.
Even more 'FWTW', the 2017 'revised Hamas manifesto' adds a fig leaf of their own, as it
attempted to distinguish between Jews or Judaism and modern Zionism. Hamas said that its fight was against the “racist, aggressive, colonial and expansionist” Zionist project, Israel, but not against Judaism or Jews. The updated platform also lacked some of the anti-Semitic language of the 1988 charter. [...]
[16:] Hamas affirms that its conflict is with the Zionist project not with the Jews because of their religion. Hamas does not wage a struggle against the Jews because they are Jewish but wages a struggle against the Zionists who occupy Palestine. Yet, it is the Zionists who constantly identify Judaism and the Jews with their own colonial project and illegal entity.
[17:] Hamas rejects the persecution of any human being or the undermining of his or her rights on nationalist, religious or sectarian grounds. [...]
Now generally speaking, I'm not sure how much Hamas talks about human rights, as they don't seem to use the term as such (while rejecting 'persecution' of Jews). And the document doesn't mention citizenship either, but does mention democracy
[28:] Hamas believes in, and adheres to, managing its Palestinian relations on the basis of pluralism, democracy, national partnership, acceptance of the other and the adoption of dialogue.
The degree of credibility of these statements is another matter, of course.