(And the Jews said, "The Christians are [standing] on nothing," and the Christians said, "The Jews are [standing] on nothing.")
The intended meaning refers to the Jews of Medina and the delegation of the Christians of Najran, who disputed in the presence of the Messenger of Allah—may Allah bless him and grant him peace—and traded insults. The Jews denied the Gospel and the prophethood of Jesus, peace be upon him, while the Christians denied the Torah and the prophethood of Moses, peace be upon him. The definite article (al) in both instances is for the purpose of identifying specific groups (lil-‘ahd).
It is also said that the meaning is general—all Jews and all Christians—as a report concerning past nations, intended to rebuke those present with the Prophet—may Allah bless him and grant him peace—and to console him, as they had previously denied the messengers and the scriptures before him. In this view, the definite article in both instances denotes the genus (lil-jins).
The first view is what is narrated in the Asbab al-Nuzul (Occasions of Revelation), and according to it, it is possible that the speaker is any individual from either party, which is the apparent meaning. It is also possible that the intended meaning refers to two specific men: a man from the Jews named Nafi' ibn Harmala, and a man from the Christians of Najran; attributing this to the entirety of both groups because it occurred on the part of some of them is a known method among the Arabs in both their poetry and prose. This is a clarification of each faction declaring the other misguided specifically, following the preceding clarification of their declaring everyone else misguided generally.
The phrase "on nothing" (‘ala shay’) is the predicate of "is not" (laysat). According to some, this involves the omission of an adjective, meaning: "nothing to be reckoned with in religion," because it is known that both parties are, in a sense, "upon something." The first view does not require assuming such an omission. There is a great hyperbole in the original phrasing, because "a thing" (al-shay’), as indicated by the speech of Sibawayh, is that which can be known and reported upon. When it is negated absolutely, it becomes a hyperbole regarding the lack of consideration for what they are upon, becoming akin to saying "less than nothing."
"While they recite the Scripture" is a state (hal) pertaining to both groups, by making them the agents of a single verb so as not to necessitate the application of two operators to a single object. That is, they said that while they were cognizant of what was in their scriptures, which speak contrary to what they say. In this, there is a reprimand for them and guidance for the believers that one who is knowledgeable of the Qur’an ought not to say what contradicts what it contains. The intended meaning of "the Scripture" is the genus, thus it applies to the Torah and the Gospel. It is also said that it refers to the Torah, as the Christians also follow it.
"Likewise said those who do not know" refers to the polytheist Arabs, according to the majority. Others say it refers to the polytheists of Quraysh, or to nations that existed before the Jews and the Christians. As for the claim that it refers to the Jews themselves, with their statement being repeated as being like the statement of the Christians, and knowledge being denied to them because they did not benefit from it, the apparent meaning is that it is a statement of "those who do not know."
The kaf in "likewise" (kadhalika) is in the accusative case, acting as an adjective for a suppressed verbal noun governed by a preceding verb "said" (qala). That is: "a saying like the saying of the Jews and Christians said those who do not know." In this reading, "like their saying" is governed by "know" (ya'lamun), and "saying" signifies belief. Or, it may be said that it is the direct object, or a substitute for the place of the kaf. It is also said that "likewise" (kadhalika) is the object, and "like" (mithla) is an absolute object (maf'ul mutlaq). The intent is to liken the spoken statement to the spoken statement in its result and conclusion, and to liken the act of saying to the act of saying in its origin from mere whim, passion, and partisanship.
"Allah will judge between them on the Day of Resurrection concerning that over which they used to differ." This means between the Jews and the Christians—not between all three factions—because the progression of the composition is to clarify the state of those two factions, while the mention of the others' statements serves to demonstrate the complete invalidity of their own. "Judgment" (hukm) means the final decision and adjudication.
"On the Day" is connected to "will judge," as is what follows it; there is no harm in the difference of meaning. "Concerning that" is connected to "they differ," not to "they used to." It is placed before the verb to preserve the rhyming endings of the verses.