Charles Chapman, Matthew Henry: His Life and Times - A Memorial and a Tribute, pp. 49-50:
But at that time, when Noncomformists were persecuted so bitterly, and when special danger would attend a young man's piety, [Philip Henry] wisely decided not to send Matthew to Oxford, but allowed him, after leaving Mr. [Thomas] Doolittle, to pursue his studies at Gray's Inn, London, where many have laid the foundation of their legal greatness. Although Matthew pursued his studies with diligence and care, it appears that he never seriously thought of the law as a profession. His heart's desire was to preach the Gospel. However, by studying there he had opportunities of forming acquaintance with men of some consideration, of hearing the most eminent Episcopalian and Nonconformist divines, and of variously filling up his time with profit until he could see his way clear to the Christian ministry. The influence his legal studies is seen in many parts of his writings. Very often there will be found in his Commentary, Latin and English quotations which do not come in the usual course of classical or theological reading, and there is often a use of terms which only a lawyer would think of employing.
Henry on Gen. 8.15-29:
Noah was able to give a very good account of his charge; for of all that were given to him he had lost none, but was faithful to him that appointed him, pro hac vice—on this occasion, high steward of his household.
Though [Phinehas] was not yet the high priest, yet he might be delegated pro hac vice—for this particular occasion, to bear the urim and thummim, as 1 Sa. 23:6.
Non est distinguendum, ubi lex non distinguit—We are not allowed to make distinctions which the law does not....Qui tacet, consentire videtur—Silence gives consent.
But if the homicide was not voluntary, nor done designedly, if it was without enmity, or lying in wait (v. 22), not seeing the person or not seeking his harm (v. 23), which our law calls chance-medley, or homicide per infortunium—through misfortune, in this case there were cities of refuge appointed for the manslayer to flee to. By our law this incurs a forfeiture of goods, but a pardon is granted of course upon the special matter found.
These are but a few instances of the legal background which permeates Henry's writing. Like many Reformers and Puritans before him -- including John Calvin, Theodore Beza, Philip Melanchthon, Johannes Œcolampadius, François Hotman, Philippe de Mornay, Nathaniel Ward, John Winthrop (also studied at Gray's Inn), Johannes Althusius, and Andrew Melville, to name a few -- Henry brought an interest and justice and precision to bear upon his interest in theology, the queen of sciences. As twin ordinance of God, both magistracy and ministry intersect on so many points of morality, ethics and Biblical jurisprudence, that it is not surprising that the study of law and the study of ministry have influenced one another. One thinks of the profound effects of the Reformation not only upon the church, but upon civil jurisprudence. Christopher Goodman's How superior Powers ought to be obeyed of their subjects, and wherein they may lawfully be by God's word disobeyed and resisted; Samuel Rutherford's Lex Rex; Nathaniel Ward's Body of Liberties; and so many more like treatises grounded in the word of God concerning the duties of magistrates and citizens have left their mark on society. Freedom in Christ, brought by the gospel, has always engendered both respect for the law, as well as a desire to promote the common welfare, and to resist tyranny and oppression. And students of law, like Matthew Henry, have often seen their way, by the grace of God, to become students of our great Lawgiver, and Advocate, Christ.
Thomas M'Crie, Life of Andrew Melville, pp. 22-23:
Every person versant in its literary history must have been particularly struck with the union of the study of theology and law. Law, when properly viewed, is a noble, and in some sense a divine science. When, instead of being made to rest on the arbitrary dictates of mere will, whether exerted by individuals or communities, on the prescriptions of custom, or on the uncertain deductions of indeterminable expediency, the Law of Nations is founded, as it always ought to be, on the Law of Nature, and the eternal principles of equity and justice sanctioned by the Supreme Legislator, the study of it is closely allied to that of theology. And to represent them as discordant, or as incapable of affording aid to each other, is to injure both, and is as absurd as it would be to divorce and dissever the great ends which they respectively aim at,—the promoting of the temporal and spiritual welfare of mankind. We meet with few of the writers of this period who excelled in one of these branches without being also well acquainted with the other. As religion is the common concern of all men, and as the public mind was then deeply interested in the controversies relating to it, we are not greatly surprised at the accounts which are given of the extensive acquaintance with the Scriptures, and with ecclesiastical history, which was possessed by many distinguished civilians and statesmen—by such men as Hottoman, and Godefroy, and Grotius, Languet, and Mornay, and St Aldegonde. But we are not equally prepared to admit the statement, although well authenticated, that the chief divines of the Reformed Church were intimately acquainted with the principles of jurisprudence, and qualified, by the course of study which they had pursued, to give their advice on questions relating to government and the administration of laws. Not to mention Calvin, Beza, and other foreign theologians, it would be easy to establish the fact by referring to not a few in our own country, as Row, Craig, Pont, Arbuthnot, and Adamson. This may be ascribed partly to the passion which those who addicted themselves to learning at that period felt to "intermeddle with all knowledge;" and partly to the superior gratification which this manly study yielded, in comparison with the dry and disgusting logic which had so long been exclusively cultivated in the schools. But it is chiefly to be traced to a new feeling, which recent events had produced, and which had for its direct object the promotion of the public good. This was the effect of the late reformation of religion; and at the same time one of the moral forces by which that mighty revolution exerted its influence upon the sentiments of mankind in favour of civil liberty and the amelioration of government. It is a favourite maxim with many in the present day, that the benefits which we owe to the Reformation are to be regarded as the ulterior and remote results of that event, rather than effects contemplated and intended by the reformers. It would be absurd to give an absolute negative to this proposition; but there is much less truth in it than those who announce it with such oracular importance imagine. Many of those actions which we are apt to impute to turbulence, or to clerical ambition and officiousness, and which we are prone to stigmatise as the offspring of bigotry and intolerance, we would, if better acquainted with the principles of the actors, and more attentive to the circumstances in which they were placed, see reason to ascribe to more enlightened and patriotic views.