Matt14:
Where do we find the command by Jesus that there would be an office of pope with successors?
Your question is more about Apostolic Succession than about the Pope. The office of Pope, based on scriptural warrant, which I will post below, was consolidated as a result of particular needs. The Pope is a bishop. He is a central figure among other bishops, but his office is always that of a bishop.
John 20:19-23, shows Jesus breathing on the 10 and committing to them Holy Spirit with the power to forgive sins. Since forgiveness of sins is what Calvary was all about, Jesus commits the fruit of Calvary in a particular way to the Apostles. The Catholic view is that this
had to be a transmissible charism in order for the Church to carry out its mission.
Petrine primacy rests on these scriptures:
The
word “Pope” comes later. It is an affectionate term for “father” because the Church is a family. Although the word “Pope” comes later, the central place of Peter among the Apostles is solidly scriptural.
Start here:
catholic.com/library/church_papacy.asp
The relevant Scriptures are
Mt. 16:13-19
Now when Jesus came into the district of Caesarea Philippi, he asked his disciples, “Who do men say that the Son of man is?” And they said, “Some say John the Baptist, others say Elijah, and others Jeremiah or one of the prophets.” He said to them, “But who do you say that I am?” Simon Peter replied, “You are the Christ, the Son of the living God.” And Jesus answered him, “Blessed are you, Simon Bar-Jona! For flesh and blood has not revealed this to you, but my Father who is in heaven. And I tell you, you are Peter, and on this rock I will build my church, and the powers of death shall not prevail against it. I will give you the keys of the kingdom of heaven, and whatever you bind on earth shall be bound in heaven, and whatever you loose on earth shall be loosed in heaven.”
**Luke 21:31-32 **
“Simon, Simon, behold, Satan demanded to have you [Greek: you all], that he might sift you like wheat, but I have prayed for you [Greek: you singular = Simon] that your faith may not fail; and when you have turned again, strengthen your brethren.”
**John 21:15-19 **
When they had finished breakfast, Jesus said to Simon Peter, “Simon, son of John, do you love me more than these?” He said to him, “Yes, Lord; you know that I love you.” He said to him, “Feed my lambs.” A second time he said to him, “Simon, son of John, do you love me?” He said to him, “Yes, Lord; you know that I love you.” He said to him, “Tend my sheep.” He said to him the third time, “Simon, son of John, do you love me?” Peter was grieved because he said to him the third time, “Do you love me?” And he said to him, “Lord, you know everything; you know that I love you.” Jesus said to him, “Feed my sheep. Truly, truly, I say to you, when you were young, you girded yourself and walked where you would; but when you are old, you will stretch out your hands, and another will gird you and carry you where you do not wish to go.” (This he said to show by what death he was to glorify God.) And after this he said to him, “Follow me.”
For the authority to pass the Apostolic commission down to successors:
Acts 1:15-26
In those days Peter stood up among the brethren (the company of persons was in all about a hundred and twenty), and said, “Brethren, the scripture had to be fulfilled, which the Holy Spirit spoke beforehand by the mouth of David, concerning Judas who was guide to those who arrested Jesus. . . . For it is written in the book of Psalms, ‘Let his habitation become desolate, and let there be no one to live in it’; and ‘His office let another take.’ So one of the men who have accompanied us during all the time that the Lord Jesus went in and out among us, beginning from the baptism of John until the day when he was taken up from us – one of these men must become with us a witness to his resurrection.” And they put forward two, Joseph called Barsabbas, who was surnamed Justus, and Matthias. . . . And they cast lots for them, and the lot fell on Matthi’as; and
he was enrolled with the eleven apostles.