I made haste Though the words are in the past tense, they denote a continued act. The prophet declares with what promptitude he dedicated himself to the service of God. Diligence and dispatch demonstrate the favor of his zeal. Next, in saying that he delayed not, [1] this, according to the Hebrew idiom, gives intensity to the idea conveyed by the phrase, I made haste As among the Hebrews, to speak and not to keep silence is equivalent to speaking freely, unreservedly, and without dissimulation, as the occasion demands, so to make haste and not delay is to run quickly without doubt or delay. If we reflect on our own listlessness, and on the snares which Satan never fails to put in our way, we will at once perceive that these words are not added in vain. For let a man be ever so desirous of applying himself truly and heartily to the righteousness of God, yet, according to Paul, we know that "he does not the thing that he would," (Romans 7:15, 18, 19). Although no outward obstacle may stand in our way, yet we are so retarded by impediments within, that nothing is more difficult than to make haste to keep the law of God. At the same time we must remember, that the prophet is here speaking comparatively in reference to those who are chargeable with procrastination during the greater part of their life, and who draw near to God, not only hesitatingly and tardily, but also purposely loiter in their course, or else prevent themselves from coming by their tortuous ways. The prophet did not manifest more alacrity in serving God than Paul; all he intends, therefore, is, that having surmounted all obstacles which lay in his way, he prosecuted his journey with rapidity. And by his example he teaches us, that the pleas which we offer in extenuation of our indolence, either arising from the impediments presented by the world or our own infirmity, are vain and frivolous.

Footnotes

1 - "The original word, which we translate delayed not, is amazingly emphatical. vl' htmhmhty velo hethmahmaheti, I did not stand what, what, whating; or, as we used to express the same sentiment, shilly-shallying with myself; I was determined, and so set out. The Hebrew word, as well as the English, strongly marks indecision of mind, positive action being suspended, because the mind is so unfixed as not to be able to make a choice." -- Dr Adam Clarke

I made haste - This language further describes the process of conversion. There was no delay; there was no excuse offered. He acted at once under his conviction of what was right. He did not ask permission to defer it to a future time; he did not attempt to avoid the duty; not plead inability; he did not give himself merely to the "use of means;" he did not rely on prayer, and reading, and reflection; but "he did the thing, and he did it at once." This is conversion; and if all convicted sinners would follow this example, and do at once that which they are commanded to do, and which they know they ought to do, there would be in no case any difficulty about conversion, for the main difficulty in conversion lies in the fact that the sinner is not willing to obey God at once; that he will not break away from his sins; that he endeavors to excuse himself; that he pleads for delay; that he waits for God to do what he himself ought to do.
And delayed not to keep thy commandments - I did not continue to go on in a course of sin, but I forsook my sin and obeyed.

Thirdly. I made haste, and delayed not - He did this with the utmost speed; and did not trifle with his convictions, nor seek to drown the voice of conscience.
The original word, which we translate delayed not, is amazingly emphatical. ולא התמהמהתי velo hithmahmahti, I did not stand what-what-whating; or, as we used to express the same sentiment, shilly-shallying with myself: I was determined, and so set out. The Hebrew word, as well as the English, strongly marks indecision of mind, positive action being suspended, because the mind is so unfixed as not to be able to make a choice.

I made haste, and delayed not to keep thy commandments. As soon as he was sensible of his duty, he immediately complied with it; he consulted not with flesh and blood, but at once yielded a cheerful obedience to the commands of God. Instances of evangelical obedience of this kind we have in the three thousand converts, in Saul, and in the jailer and his house, Acts 2:41.