The Sifre to Numbers is evidently a midrash which originated in R. Simeon's school, and which has all the peculiarities and characteristics of such a work. It follows the same principles of exposition as does the Mekilta; the same group of tannaim appears, and the same technical terms are employed (see Mekilta; to the examples there given may be added טעמו של דבר מגיד מפני מה, Num. viii., for which the Sifra to Lev. xxi. 12 uses the expression להגיד מה גרם). There are also many material points of similarity with the Mekilta: thus Sifre 2 agrees literally with Mek., Mishpaṭim, 6; Sifre 65 with Mek., Bo, 5; Sifre 71 with ib. 15; Sifre 142 with ib. 5. The haggadic portions likewise contain many parallel passages (comp. the collation in D. Hoffmann, l.c. p. 54, though Sifre 64 and Mek., Beshallaḥ, 1 should not be included, since these two passages disagree on one point).
It is an especially noteworthy fact that the explanation in Sifre, Num. 7 of the law regarding a woman charged with adultery corresponds with a view expressed by R. Ishmael, and also with the prescribed halakah, according to which, one witness being sufficient to convict, the water-test is not necessary. The explanation given in the Sifre to Numbers thus contradicts the explanation in Soṭah 31a and in Sifre, Deut. 188. The view expressed in Babli is curious: it cites (Soṭah 2a and 31b) the explanation of the Sifre to Numbers, and adds thereto: ואמר רחמנא תרי לית בה אלא חד והיא לא נתפשה אסורה, whereas the deduction should read to the contrary, תרי לית בה אלא חד היתה שותה. Babli, which evidently does not know R. Ishmael's view, tries to interpret the baraita in the sense of the prescribed halakah. But the baraita must in fact be interpreted in the opposite sense, namely, as following the view of R. Ishmael, who, because עד always implies "two," as appears from Yer. Soṭah 20d, demands also in the case of a woman charged with adultery two witnesses of the alleged crime.
The passage introduced by the phrase סתם ספרי (Sifre 161) likewise echoes R. Ishmael's views; and the same is true of Sifre 21 as compared with Sifre 7. The beginning of Sifre 7 appears to be, strangely enough, an anonymous halakah expressing the opposite opinion (comp. Yer. Soṭah 16b), though this also may at need be harmonized with R. Ishmael's view. Sifre 39 likewise follows R. Ishmael's view, according to Ḥul. 49a. These and other less cogent reasons seem to indicate that the Sifre to Numbers originated in R. Ishmael's school, though this does not exclude the assumption that the editor in addition borrowed much from R. Simeon's midrash (comp. D. Hoffmann, l.c. p. 54) and other less-known midrashim.
Similarly, some halakic differences between the Sifre and the Mekilta may be pointed out: Sifre, Deut. 123 differs from Mek., Mishpaṭim, 1; ib. 122 from Mek., Mishpaṭim, 2, which latter reproduces R. Ishmael's view (comp. D. Hoffmann, l.c. pp. 68, 69). All these points indicate that the Sifre to Deuteronomy originated in R. Akiba's school; and, as several anonymous passages may be cited to express the views of R. Simeon, this midrash may with a fair degree of certainty be ascribed to him. Such anonymous passages are found in Sifre 72-74, several sections of which Mak. 17a identifies as R. Simeon's interpretations. The same appears to be the case in Sifre 94, compared with Sanh. 112a; ib. 103 with Ḳid. 57a; ib. 121 with Sanh. 46b. Sifre 166, and perhaps also 165, likewise correspond with R. Simeon's views (comp. Ḥul. 136b; Tosef., Ḥul. ix. 2, x. 1); while in Sifre 303 the explanation of לא בערתי ממנו בטמא, and the omission of בכורים, also imply an agreement therewith (comp. Yeb. 73b and Bik. ii. 2).
Sifre 107, however, by no means corresponds with the passage תני ר"י in Yer. Er. 20c (Hoffmann, Zur Einleitung, etc., p. 67), but expresses just the opposite view. Sifre, Deut. 171, s.v. ד"א, corresponds perhaps with Meg. 25a, s.v. תנא דבי ר"י ; and Sifre 104 with the view of R. Ishmael in Mek., Mishpaṭim, 201, according to the correct reading of Yalḳuṭ, which has ר"י instead of ר"ש. It thus appears that the editor introduces the midrashim from R. Ishmael's midrash with the phrase ד"א. D. Hoffmann (l.c. p. 70) concludes from Pes. 68a and 71a that the editors of the Babylonian Talmud possessed the Sifre in another edition than the present one, which he takes to be a Palestinian edition. But the former passage indicates merely that the Amoraim occasionally had not memorized the baraitot perfectly, an instance of inaccuracy with regard to the Sifre being evident in Ḥul. 74a (comp. Tos. ad loc., s.v. להאי).
It may be said in general of the Sifre to Numbers and also of that to Deuteronomy that they are defective in many passages, and that the Amoraim probably possessed more trustworthy copies (comp. D. Hoffmann, l.c. pp. 53, 68). Even Rashi and the Leḳaḥ Ṭob quote from the Sifre passages which are no longer extant (comp. Grätz Jubelschrift, p. 4, notes 5, 7-10). While the middle, halakic portion of the Sifre to Deutronomy belongs to Akiba's school, the haggadic portions preceding and following it seem to come from works of R. Ishmael's school. This appears clearly in the first part, which shows many formal and material similarities with the Mekilta. In regard to the latter portion, it may be said that Sifre, Deut. 344 reproduces R. Ishmael's view on the question at issue (comp. B. Ḳ. 113a). As for the halakic midrash, it may be said that, in contradistinction to the haggadic part, the collector used, aside from R. Ishmael's midrash, that of R. Simeon (comp. Sifre 28 with Lev. R. i.; ib. 37 with Gen. R. lxxxv.; ib. 40 with Lev. R. xxxv.; ib. 47 with Gen. R. xii.; ib. 336 with Gen. R. lxxxii.; ib. 313 with Tan., ed. S. Buber, p. 72).
The final redaction of the Sifre must have been undertaken in the time of the Amoraim, since some of them, e.g., Rabbai Bannai and [Rabbi Jose ben Ḥanina, are mentioned therein. Both the Sifre to Numbers and that to Deuteronomy are divided into sections. The earliest extant edition of the Sifre is that of Venice, 1545. Other editions are: Hamburg, 1789; Sulzbach, 1802; with commentary by David Pardo, Salonica, 1804; with commentary by Abraham Lichtenstein (זרא אברהם), part i., Dyhernfurth, 1811; part ii., Radwill, 1820; ed. Friedmann, Vienna, 1864. A translation of the Sifre is found in Biagio Ugolini, Thesaurus, vol. xv.