Frank J. Wilstach, comp. A Dictionary of Similes. 1916.

Firm

Firm as the shaft that props the towering dome.
—Æschylus

Firm as the solid base of this great world.
—Mark Akenside

Firm as adamant.
—Anonymous

Firm as a mountain.
—Anonymous

Firm as the granite base of Mount Washington.
—Anonymous

Firm as the iron hills.
—Anonymous

Firm as the budding fruit.
—Ariosto

Firm as well-cured olives.
—Aristophanes

Stand firm like a rock.
—Marcus Aurelius

Firm as butchers.
—Francis Bacon

Firm as the heart of a mountain.
—Ambrose Bierce

Firm in his sinew as the hind leg of a stag.
—Edward Bulwer-Lytton

Firmer than heaven and earth.
—John Bunyan

Firm as a fortress.
—Lord Byron

Held firm, like a wall of rock.
—Thomas Carlyle

Firm-founded, like the bamboo’s clamping roots.
—Chinese

Firm as Sparta’s king.
—Sir Francis Doyle

Rock firm as facts.
—Thomas Hardy

Firm as the band that clasps the antlered spoil.
—Oliver Wendell Holmes

Firm as the rooted mountain rock.
—Oliver Wendell Holmes

Firm as Atlas.
—Robert Jephson

Firm as steel.
—Virginia W. Johnson

Firm as the tread of lions.
—Richard Le Gallienne

Firm as the oak on rocky heights.
—Edward Lovibond

Firm as Nature’s self.
—James Russell Lowell

Firm as a pillar.
—George Meredith

Hands firm as driven stakes.
—George Meredith

Firm as the poles, or earth, which never move.
—George Sandys

Firm as faith.
—William Shakespeare

Firm as rocky mountains.
—William Shakespeare

Firm as the world’s centre.
—Percy Bysshe Shelley

Firm as dust and fixed as shadows.
—Algernon Charles Swinburne

Firm as a stone.
—Old Testament

As virtue, firm.
—William Thomson

Firm as the fabled throne of Grecian Jove.
—William Thomson

Firm as the castle’s feudal roof.
—Thomas Warton

As firm as rock in ocean.
—William Whitehead

Firm as the chain of rocks which guard the strand.
—William Wilkie

Firm and unflinching, as the lighthouse reared
On the Island-rock.
—William Wordsworth

Firm as solid crystal.
—William Wordsworth