I believe it to hearken back to the admonition in Ezekiel:
17 Son of man, I have made thee a watchman unto the house of Israel: therefore hear the word at my mouth, and give them warning from me.
18 When I say unto the wicked, Thou shalt surely die; and thou givest him not warning, nor speakest to warn the wicked from his wicked way, to save his life; the same wicked man shall die in his iniquity; but his blood will I require at thine hand.
19 Yet if thou warn the wicked, and he turn not from his wickedness, nor from his wicked way, he shall die in his iniquity; but thou hast delivered thy soul.
20 Again, When a righteous man doth turn from his righteousness, and commit iniquity, and I lay a stumbling-block before him, he shall die: because thou hast not given him warning, he shall die in his sin, and his righteousness which he hath done shall not be remembered; but his blood will I require at thine hand.
21 Nevertheless if thou warn the righteous man, that the righteous sin not, and he doth not sin, he shall surely live, because he is warned; also thou hast delivered thy soul.
And re-iterated in Ezekiel 33