Joshua 7:3
"And they returned to Joshua, and said unto him, Let not all the people go up; but let about two or three thousand men go up and smite Ai; and make not all the people to labour thither; for they are but few."
Cross References (ranked by relevance)
Strive to enter in at the strait gate: for many, I say unto you, will seek to enter in, and shall not be able.
And beside this, giving all diligence, add to your faith virtue; and to virtue knowledge;
The soul of the sluggard desireth, and hath nothing: but the soul of the diligent shall be made fat.
The desire of the slothful killeth him; for his hands refuse to labour.
Wherefore the rather, brethren, give diligence to make your calling and election sure: for if ye do these things, ye shall never fall:
Let us labour therefore to enter into that rest, lest any man fall after the same example of unbelief.