In writing "The Treasury of David," seven volumes, Mr. Spurgeon spent a considerable part of twenty years. "During the whole of that period," says the Rev. Robert Shindler, in his valuable life of Spurgeon, "Mr. J. L. Keys, one of Mr. Spurgeon's secretaries, continued to search the library of the British Museum, and other libraries, and to cull from every available source everything worthy of quotation upon the book of Psalms." Over one hundred and twenty thousand volumes have been sold. Dr. Philip Schaff thought it "the most important homiletical and practical work of the age on the Psalter."
Of Spurgeon's "Morning by Morning" and "Evening by Evening," for home reading and devotions, over two hundred thousand copies have been sold.
"Commenting and Commentaries" was a work of great labor, showing his students and others what to use. "If I can save a poor man," he wrote, "from spending his money for that which is not bread, or, by directing a brother to a good book, may enable him to dig deeper into the mines of truth, I shall be well repaid. For this purpose I have toiled, and read much, and passed under review some three or four thousand volumes."
Twenty-seven volumes of the Sword and Trowel, Mr. Spurgeon's magazine, have had an enormous circulation. This is also true of "Lectures to My Students," abounding in sensible suggestions. To those about to become ministers he says:—
"Avoid little debts, unpunctuality, gossiping, nicknaming, petty quarrels, and all other of those little vices which fill the ointment with flies....
"Even in your recreations, remember that you are ministers.... His private life must ever keep good tune with his ministry, or his day will soon set with him, and the sooner he retires the better; for his continuance in his office will only dishonor the cause of God and ruin himself."
Spurgeon urged private prayer upon his young men, and related this incident from Father Faber: "A certain preacher, whose sermons converted men by the scores, received a revelation from heaven that not one of the conversions was owing to his talents or eloquence, but all to the prayers of an illiterate lay brother, who sat on the pulpit steps, pleading all the time for the success of the sermon."
The great John Knox used to say he "wondered how a Christian could lie in his bed all night and not rise to pray."
Of public prayer, Spurgeon said, "Do not let your prayer be long.... 'He prayed me into a good frame of mind,' George Whitefield once said of a certain preacher, 'and if he had stopped there, it would have been very well; but he prayed me out of it again by keeping on.'"
Of the sermon he said, "Preach Christ always and evermore. He is the whole gospel.... Your pulpit preparations are your first business. A man great at tea-drinkings, evening parties, and Sunday-school excursions is generally little everywhere else.