Let the thing go without hindrance. The phrase occurs in Chaucer and in Shakespeare.
1847. If you have the least hankerin’ arter the mean varmint, in course I’ll let him slide.—Robb, ‘Streaks of Squatter Life,’ &c., p. 122 (Phila.). (Italics in the original.)
1850. Oil the press well, and let her slide.—Frontier Guardian, Feb. 6.
1851. The old man had told him to let it slide at fifteen rather than not sell [the cotton].—‘Polly Peablossom’s Wedding,’ &c., p. 32.
1853. “Oh, let the poker slide, Judge,” replied Sol; “some other time, when I want a stake, or get into a scrape, I’ll make a call.”—S. A. Hammett (‘Philip Paxton’), ‘A Stray Yankee in Texas,’ p. 220.
1853. The old year will soon be gone; so we’ll let it slide.—Dow, Jun., ‘Patent Sermons,’ iii. 225.
1854. I done as Mr. Robjohn done—let it slide, let it slide.—Knick. Mag., xliv. 24 (July).
1855. When Brigham chooses to run around a snag, or over a snag, he will do so. The ship is all oak. Let her slide.—J. M. Grant at the Mormon Tabernacle, Sept. 24: ‘Journal of Discourses,’ iii. 69.
1855. It has been charged that [Mr. Banks] used the language, “let the Union slide.”—Mr. Stewart of Maryland, House of Repr., Dec. 24: Cong. Globe, p. 74.
1856. This talk about “letting the Union slide” goes for nothing with me, especially when it comes from persons who attempt to make it slide upon every opportunity.—Mr. Simmons of N.Y., the same, Jan. 16: id., p. 238.
1857. I know that you never heard brother Brigham never rebuke me for being valiant before this people. He says, “Let her go, Heber; let her slide.”—H. C. Kimball at the Bowery, Salt Lake City, Aug. 2: ‘Journal of Discourses,’ v. 133.
1858. If you can’t “come up to the scratch,” why I must “let you slide.”—J. G. Holland, ‘Titcomb’s Letters,’ p. 141.
1860. My friend the Colonel tells me the KNICKERBOCKER never publishes communications from a farmer’s pen. Very likely; but I shall nevertheless ‘let her slide.’—Knick. Mag., lv. 413 (April).
1861. If we must give up that principle or the Union, let the idea slide.—Olympia (W.T.) Pioneer, March 1.
