97 We have frequently admonished you, that love was to be understood by that praiseworthy breadth, by means of which, while we do the commandments of God, we feel no straitness. On this account also after saying above in this great Psalm, “Your commandment is exceeding broad:” in the following verse he shows wherefore it is broad: “what love have I unto Your law, O Lord!”. Love is therefore the breadth of the commandment. For how can it be that what God commands to be loved, be loved, and yet the commandment itself be not loved? For this itself is the law; “in all the day,” he says, “is my study in it.” Behold how I have loved it, that in the whole day my study is in it; or rather, as the Greek has it, “all the day long,” which more fully expresses the continuance of meditation. Now that is to be understood through all time; which is, for ever. By such love lust is driven out: lust, which repeatedly opposes our performing the commandments of the law, when “the flesh lusts against the spirit:” against which the spirit lusting, ought so to love the law of God, that it be its study during the whole day....
98. And he then adds: “You have made me to understand Your commandment above mine enemies; for it is ever with me”. For “they have indeed a zeal of God, but not according to knowledge,” etc. But the Psalmist, who understands the commandment of God above these his enemies, wishes to be found with the Apostle, “not having” his “own righteousness, which is of the law, but that which is of the faith of Christ, which is of God;” not that the Law which his enemies read is not of God, but because they do not understand it, like him who understands it above his enemies, by clinging to the Stone upon which they stumbled. For “Christ is the end of the law,” etc., “that they may be justified freely through His grace;” not like those who imagine that they obey the law of their own strength, and are therefore, though by God's law, yet still endeavouring to set up their own righteousness; but as the son of promise, who hungering and thirsty after it, by seeking, by asking, by knocking, as it were begs it of the Father, that being adopted he may receive it through His only-begotten Son....His enemies sought from the same commandment temporal rewards; and therefore it was not unto them for ever, as it was unto this man. For they who have translated “for ever” have rendered better than they who have written “for an age,” since at the end of time there can be no longer a commandment of the law....
99. But what means the following verse, “I have more understanding than my teachers”?. Who is he who had more understanding than all his teachers? Who, I ask, is he, who dares to prefer himself in understanding above all the Prophets, who not only by speaking taught with so excellent authority those who lived with them, but also their posterity by writing?...What is here said, could not have been spoken in Solomon's person....I recognise plainly Him who had more understanding than His teachers, since when He was a boy of twelve years of age, Jesus remained behind in Jerusalem, and was found by His parents after three days' space, “sitting in the temple among the doctors, hearing them and asking them questions.” The Son Himself has said, “As My Father has taught Me, I speak these things.” It is very difficult to understand this of the Person of the Word; unless we can comprehend that it is the same thing for the Son to be taught as to be begotten of the Father....“He took upon Himself the form of a servant;” for when He had assumed this form, men of more advanced age might think Him fit to be taught as a boy; but He whom the Father taught, had more understanding than all His teachers. “For Your testimonies,” He says, “are my study.” For this reason He had more understanding than all His teachers, because He studied the testimonies of God, which, as concerning Himself, He knew better than they, when He spoke these words: “You sent unto John, and he bore witness unto the truth. But I receive not testimony from man,” etc.
100. But these teachers may be understood very reasonably to be those aged men, of whom he presently says, “I am wiser than mine elders”. And this seems to me to be repeated here thus, that that age of His which is well known to us in the Gospel might be called to our remembrance; the age of boyhood, during which He was sitting among the aged, understanding more than all His teachers. For the smaller and the greater in age are wont to be termed younger and elder, although neither of them has arrived at or approached old age; although if we are concerned to seek in the Gospel the express term, elders, more than whom He understood, we find it when the Scribes and Pharisees said unto Him, “Why do Your disciples transgression the tradition of the elders? For they wash not their hands when they eat bread.” Behold the transgression of the tradition of the elders is objected to Him. But He who was wiser than His elders, let us hear what answer He made them. Why do ye also, He asked, “transgress the commandment of God by your tradition?”...
101. But what comes next, does not seem to apply to the Head, but to the Body: “I have refrained my feet from every evil way, that I may keep Your words”. For that Head of ours, the Saviour of the Body Himself, could not be borne by carnal lust into any evil way, so that it should be needful for Him to refrain His feet, as though they would go there of their own accord; which we do, when we refrain our evil desires, which He had not, that they may not follow evil ways. For thus we are able to keep the word of God, if we “go not after our evil lusts,” so that they attain unto the evils desired; but rather curb them with the spirit which lusts against the flesh, that they may not drag us away, seduced and overthrown, through evil ways.
102. “I have not shrunk,” he says, “from Your judgments: for You have laid down a law for me”. He has stated what made him fear, so that he refrained his feet from every evil way....Thou, more inward than my inmost self, You have laid down a law within my heart by Your Spirit, as it were by Your fingers, that I might not fear it as a slave without love, but might love it with a chaste fear as a son, and fear it with a chaste love.
103. Consider then what follows: “O how sweet are Your words unto my throat!”. Or, as it is more literally rendered from the Greek, “Your utterances, above honey and the honeycomb unto my mouth.” This is that sweetness which the Lord gives, “So that the earth yield her increase:” that we do good truly in a good spirit, that is, not from the dread of carnal evil, but from the gladness of spiritual good. Some copies indeed do not read “honeycomb:” but the majority do. Now the open teaching of wisdom is like honey; but that is like the comb which is squeezed from the more recondite mysteries, as if from cells of wax, by the mouth of the teacher, as if he were chewing it: but it is sweet to the mouth of the heart, not to the mouth of the flesh.
104. But what mean the words, “Through Your commandments I get understanding”?. For the expressions, I have understood Your commandments: and, “I get understanding through Your commandments;” are different. Something else then he signifies that he has understood from the commandments of God: that is, as far as I can see, he says, that by obeying God's commandments he has arrived at the comprehension of those things which he had longed to know....These then are the words of the spiritual members of Christ, “Through Your commandments I get understanding.” For the body of Christ rightly says these words in those, to whom, while they keep the commandments, a richer knowledge of wisdom is given on account of this very keeping of the commandments. “Therefore,” he adds, “I hate all evil ways.” For it is needful that the love of righteousness should hate all iniquity: that love, which is so much the stronger, in proportion as the sweetness of a higher wisdom does inspire it, a wisdom given unto him who obeys God, and gets understanding from His commandments.
Source: The Enarrations, or Expositions, on the Psalms (New Advent)