John 10:4-5 And when he putteth forth his own sheep, he goeth before them, and the sheep follow him: for they know his voice. And a stranger will they not follow, but will flee from him: for they know not the voice of strangers.
I’m not sure where I got it, but somehow “my sheep will hear my voice and not hear the voice of another” got stuck in my head. I can’t find a verse like that. Instead it could be summarized “my sheep will hear my voice and not recognize the voice of another”. Otherwise, according to John 10:5, the sheep can hear the voice of the good sheepherd and the voice of the stranger, however, they follow the voice they KNOW and flee from the voice they don’t recognize.
Now, how do we KNOW the Master’s voice? The answer is to have His word abide in us. What you spend time on, you will be sensitive to.
John 15:4-8 Abide in me, and I in you. As the branch cannot bear fruit of itself, except it abide in the vine; no more can ye, except ye abide in me. I am the vine, ye are the branches: He that abideth in me, and I in him, the same bringeth forth much fruit: for without me ye can do nothing. If a man abide not in me, he is cast forth as a branch, and is withered; and men gather them, and cast them into the fire, and they are burned. If ye abide in me, and my words abide in you, ye shall ask what ye will, and it shall be done unto you. Herein is my Father glorified, that ye bear much fruit; so shall ye be my disciples.