A leaden sword in an ivory scabbard. [ Proverb ]

Night, sable goddess! from her ebon throne,
In rayless majesty, now stretches forth
Her leaden sceptre over a slumbering world.
Silence, how dead! and darkness, how profound!
Nor eye, nor listening ear, an object finds;
Creation sleeps. 'Tis as the general pulse
Of life stood still, and nature made a pause;
An awful pause! prophetic of her end. [ Young ]

Light-heeled mothers make leaden-heeled daughters. [ Proverb ]

I have this while with leaden thoughts been pressed;
But I shall, in a more continuate time,
Strike off this score of absence. [ William Shakespeare ]

God comes with leaden feet, but strikes with iron hands. [ Proverb ]

Brevity and conciseness are the parents of conviction. The leaden bullet is more fatal than when multiplied into shot. [ Hosea Ballou ]