Read the article written by James White against the 2520. Note that the year he wrote this article in the official paper representing Adventist position was the very year we became a denomination. Consider also that Ellen White gave a powerful endorsement to what James White wrote in the Review:

“Then I saw that the paper [Review and Herald] would go and that it would be the means of bringing souls to a knowledge of the truth. I saw that James had not borne the burden alone but that the angels of God had assisted and had oversight of the paper.”  {13MR 299.1}  (Written December 25, 1850, at Paris, Maine.)

The Review and Herald

“Sanctify them through thy truth: thy word is truth.”
BATTLE CREEK, MICH., THIRD-DAY, JANUARY 26, 1864,
JAMES WHITE, EDITOR

The Seven Times of Lev. 26

The prophetic period of Lev. xxvi, or what has been supposed to be such, has been no small object of study among prophetical expositors. It has been supposed that the expression, “seven times,” in verses 18, 21, 24, 28, denoted a prophetic period of 2520 years, and that this period covered the time during which the throne of Israel should be and remain subverted and trodden down by oppressing powers. To rightly fix the commencement and termination of this period, became therefore a matter of consequence. Where does it commence? and where does it end? have been questions of much study, and perhaps some perplexity.

These are not the questions, however, that we propose here to discuss; for there is a question lying back of these, which demands to be answered first; namely, Is there any prophetic period brought to view at all in Lev. xxvi? We claim that there is not, and will offer a few of what are to us very conclusive reasons for this position: {January 26, 1864 JWe,

1. A series of judgments is threatened against Israel, in case they hearkened not unto God to do his commandments, before the expression, seven times, is introduced. Verses 14-17. In these judgments is included being slain before their enemies, being reigned over by those that hated them, and fleeing when none pursued them. Now if the seven times were meant to cover the period of God’s special judgments against Israel, especially of their captivity by foreign powers, these seven times should have been mentioned in connection with the first threatening of judgments of this kind. But this, as we have seen, is not the case.

2. After the threatening of these judgments, God says, verse 18, “And if ye will not for all this hearken unto me, then I will punish you seven times more for your sins.” Then follows an enumeration of the judgments to come upon them in fulfillment of this, different from the items of the first threatening, and increasing in severity.

3. If they would not for this hearken, seven times more plagues were threatened against them, “according to their sins.” Verse 21. Then again follows an enumeration of judgments to correspond, more severe still than any preceding.

4. If they would not be reformed by these things, God threatened to punish them seven times more for their sins. Verse 24. And in like manner with the foregoing, an enumeration of the judgments to be inflicted in fulfillment, immediately follows, more fearful still.

5. And if they would not hearken to God for all these things, he makes a final threat that would walk contrary to them in fury, and chastise them seven times for their sins. Verse 28. And an enumeration of the judgments to be inflicted, again immediately follows, outdoing all before, in their terrible severity. Included among them were the eating of the flesh of their sons and daughters, making waste their cities, bringing the land into such desolation that their enemies should be astonished at it, scattering them among all nations, and drawing out a sword after them in all the lands of their dispersion. With fearful minuteness all this has been fulfilled, even to the eating the flesh of their own children, as in the terrible sieges that preceded the downfall of Jerusalem.

Thus we have, first, a series of judgments threatened against Israel, without the expression, seven times, and then the declaration four times made, that God would punish them seven times for their sins, each one on condition that the former did not lead to repentance, and each one containing its own specific enumeration of judgments, distinct from those that preceded, and regularly increasing in the severity of then denunciations. Now what is meant by this repeated expression of seven times? We reply, It denotes, not the duration of the punishment, but its intensity and severity. It is well expressed in the language of verse 21, thus: “I will bring seven times more plagues upon you according to your sins.” The number seven denoting perfection, we are undoubtedly to understand by this expression, the fullness of their punishment; that the measure of their national sins, would in every case be fully equaled by the measure of their national calamities.

And this position is fully sustained by the original, as a brief criticism will show.
In references to the Hebrew, we learn from the Hebrew Concordance that the expression, seven times, in Lev. xxvi, comes from sheh-vag; and this word is expressly set down by Gesenius, in those texts, as an adverb, also in Ps. cxix, 164; Prov. xxiv, 16. In Dan. iv, 16, 25, the expression, seven times, twice occurs, where beyond question it means duration. Nebuchadnezzar was to be driven from men, and make his dwelling with the beasts of the field, until seven times should pass over him. There can be no mistaking that here the expression means a certain space of time; but here we find, not the adverb as in Lev. xxvi, but the noun, gid-dahn, defined by Gesenius, “Time, in prophetic language, for a year.” In Dan. vii, 25, where a prophetic period is brought to view in the expression, “a time and times and the dividing of time,” the same word is used. In Dan. xii, 7, where the same period is again brought to view, and in about the same language, we have another word, moh-gehd, defined by Gesenius, “Appointment of time. Spoken of a space of time, appointed and definite. In the prophetic style for a year.” It will be seen by this definition, that this word is synonymous with the one used in Dan. vii, 25, as above referred to. Now if a period of time is meant by the expression, seven times, in Lev. xxvi, one of these words should and would most assuredly have been used. And the fact that neither of these words is there used, but another word, and that an adverb, places it beyond question that no such period is there intended.

The Greek is equally definite. The Septuagint has in Lev. xxvi, heptakis, which is an adverb, signifying seven times. In Dan. iv, 16, 25, for Nebuchadnezzar’s seven times we have not heptakis, the adverb, but heptakairoi, a noun and its adjective. And in all cases where the word time occurs, denoting a prophetic period, as in Dan. vii, 25; xii, 7; Rev. xii, 14, it is from the noun kairos. Such a thing as a prophetic period based on an adverb is not to be found.

So then, there is no prophetic period in Lev. xxvi; and those who imagine that such a thing exists, and are puzzling themselves over the adjustment of its several dates, are simply beating the air. To ignore, or treat with neglect, a prophetic period where one is plainly given, is censurable in the extreme. It is an equally futile, though not so heinous, a course, to endeavor to create one where none exists.