Alcuin
Catena Aurea · Johannesevangelium 21
So when they had dined, Jesus saith to Simon Peter, Simon, son of Jonas, lovest thou me more than these? He saith unto him, Yea, Lord; thou knowest that I love thee. He saith unto him, Feed my lambs. He saith to him again the second time, Simon, son of Jonas, lovest thou me? He saith unto him, Yea, Lord; thou knowest that I love thee. He saith unto him, Feed my sheep. He saith unto him the third time, Simon, son of Jonas, lovest thou me? Peter was grieved because he said unto him the third time, Lovest thou me? And he said unto him, Lord, thou knowest all things; thou knowest that I love thee. Jesus saith unto him, Feed my sheep. He saith to him again the second time, Simon, son of Jonas, lovest thou Me? He saith unto Him, Yea, Lord; Thou knowest that I love Thee.
To feed the sheep is to support the believers in Christ from falling from the faith, to provide earthly sustenance for those under us, to preach and exemplify withal our preaching by our lives, to resist adversaries, to correct wanderers.