'Salt' in the Bible

Ye are the salt of the earth: but if the salt have lost his savour, wherewith shall it be salted? it is thenceforth good for nothing, but to be cast out, and to be trodden under foot of men.

For every one shall be salted with fire, and every sacrifice shall be salted with salt.

Salt is good: but if the salt have lost his saltness, wherewith will ye season it? Have salt in yourselves, and have peace one with another.

Salt is good: but if the salt have lost his savour, wherewith shall it be seasoned?

Let your speech be alway with grace, seasoned with salt, that ye may know how ye ought to answer every man.

Can the fig tree, my brethren, bear olive berries? either a vine, figs? so can no fountain both yield salt water and fresh.