I take what follows, having the form of knowledge, as a reason for the preceding; and it may be thus explained, -- "because thou hast the form of knowledge." For they professed to be the teachers of others, because they seemed to carry in their breasts all the secrets of the law. The word form is put for model (exemplar -- pattern); [1] for Paul has adopted morphosin and not tupon: but he intended, I think, to point out the conspicuous pomp of their teaching, and what is commonly called display; and it certainly appears that they were destitute of that knowledge which they pretended. But Paul, by indirectly ridiculing the perverted use of the law, intimates, on the other hand, that right knowledge must be sought from the law, in order that the truth may have a solid basis.

Footnotes

1 - The same word occurs only in 2-Timothy 3:5, "morphosin eusebeias -- the form of godliness." It is taken here in a good sense, as meaning a sketch, a delineation, an outline, a representation, or a summary. Chalmers renders the words thus, -- "The whole summary of knowledge and truth which is in the law." Some understand by knowledge what refers to morals or outward conduct, and by truth what is to be believed. Others regard them as an instance of Hebrewism, two substantives being put, instead of a substantive and an adjective; the phrase would then be, "true knowledge." -- Ed.

Of the foolish - The word "foolish" is used in the Scriptures in two significations: to denote those who are void of understanding, and to denote the wicked. Here it is clearly used in the former sense, signifying that the Jew esteemed himself qualified to instruct those without knowledge.
Of babes - This is the literal meaning of the original word. The expression is figurative, and denotes those who were as ignorant as children - an expression which they would be likely to apply to all the Gentiles. It is evident that the character bare given by Paul to the Jews is one which they claimed, and of which they were proud. They are often mentioned as arrogating this prerogative to themselves, of being qualified to be guides and teachers of others; Matthew 15:14; Matthew 23:2, Matthew 23:16, Matthew 23:24. It will be remembered, also, that the Jews considered themselves to be qualified to teach all the world, and hence evinced great zeal to make proselytes. And it is not improbable (Tholuck) that their Rabbies were accustomed to give the names "foolish" and "babes" to the ignorant proselytes which they had made from the pagan.
Which hast the form of knowledge - The word translated here as "form" properly denotes a delineations or picturing of a thing. It is commonly used to denote also the appearance of any object; what we see, without reference to its internal character; the external figure. It sometimes denotes the external appearance as distinguished from what is internal; or a hypocritical profession of religion without its reality; 2-Timothy 3:5. "Having the form of godliness, but denying its power." It is sometimes used in a good, and sometimes in a bad sense. Here it denotes that in their teaching they retained the semblance, sketch, or outline of the true doctrines of the Old Testament. They had in the Scriptures a correct delineation of the truth. Truth is the representation of things as they are; and the doctrines which the Jews had in the Old Testament were a correct representation or delineation of the objects of knowledge; compare 2-Timothy 1:13.
In the law - In the Scriptures of the Old Testament. In these verses the apostle concedes to the Jews all that they would claim. Having made this concession of their superior knowledge, he is prepared with the more fidelity and force to convict them of their deep and dreadful depravity in sinning against the superior light and privileges which God had conferred on them.

An instructer of the foolish, etc. - Ye believe the Gentiles to be babes and fools when compared with yourselves; that ye alone possess the only true knowledge; that ye are the only favourites of Heaven; and that all nations must look up to you as possessing the only form of knowledge, μορφωσιν της γνωσεως, the grand scheme and draught of all true science, of every thing that is worthy to be learned: the system of eternal truth, derived from the law. If, therefore, ye act not as becomes those who have such eminent advantages, it must be to your endless disgrace and infamy.

An instructor of the foolish, a teacher of babes, which hast the (o) form of knowledge and of the truth in the (p) law.
(o) The way to teach and to form others in the knowledge of the truth.
(p) As though he said that the Jews under a pretence of an outward serving of God, attributed all to themselves, when in reality they did nothing less than observe the Law.

An instructor of the foolish,.... All men in a state of unregeneracy are foolish, and need instruction; here the common people among the Jews, who knew not the law, are meant; it was very usual to call anyone of their doctors and masters "an instructor": it follows,
a teacher of babes; either in age or in understanding; such who taught either of them were called by the Jews , "teachers of babes". Thus they paraphrase the text in Daniel 12:3,
"they that be wise, shall shine as the brightness of the firmament. This is the Judge who judges, the judgment of truth truly, and the collectors of alms: and they that turn, many to righteousness, as the stars for ever and ever; these are, , "the teachers of babes" (z).''
Though these are said (a) to be inferior to the wise men, or doctors:
which hast the form of knowledge, and of the truth in the law: they had not a true knowledge of the law; only a draught and scheme, the outward form of the law, and a mere shadow and appearance of the knowledge of the truth of it. From hence the apostle would have it concluded, that though the Jews had the law, and in some sense knew it, yet inasmuch as they did not perform it, they could not be justified by it; and that even their teachers, their greatest masters and doctors, were very deficient, as appears from what follows; and since they could not be instilled by it, who taught others the knowledge of it, the hearers of it could not expect justification from it.
(z) T. Bab. Bava Bathra, fol. 8. 2. & 21. 1, 2. Maimon. Hilchot Talmud Tora, c. 2. sect. 1. (a) Gloss in Sota, fol. 49. 1.

hast the form of knowledge and of the truth in the law--not being left, as the heathen are, to vague conjecture on divine things, but favored with definite and precise information from heaven.

Having the form of knowledge and truth - That is, the most accurate knowledge of the truth.