Do you have examples of that from the Gospels?
The question wasn't: did Jesus speak Aramaic. The question is: do we have texts that record what he said and did that are written in Aramaic? Without those you cannot know what he said in Aramaic. All we have are the manuscripts in Greek.
Odd that Paul didn't bother to mention it.
Peter was an Apostle. What he spoke was revelation. What all the Apostles spoke was revelation. Peter wouldn't need to speak excathedra because the fullness of revelation (including the scriptures) came from him and the other Apostles.
Actually, Matthew was probably written in Aramaic first and than greek. We see the evidence from the early church fathers again:
Around
180 Irenaeus of Lyons wrote that:
Matthew also issued a written Gospel among the Hebrews in their own dialect, while Peter and Paul were preaching in Rome and laying the foundation of the Church. After their departure, Mark, the disciple and interpreter of Peter, did also hand down to us in writing what had been preached by Peter. Luke also, the companion of Paul, recorded in a book the Gospel preached by him. Afterwards John, the disciple of the Lord, who also had leaned upon his breast, did himself publish a Gospel during his residence at Ephesus in Asia. (Against Heresies 3:1:1)
Fifty years earlier Papias, bishop of Hieropolis in Asia Minor, wrote,
"Matthew compiled the sayings [of the Lord] in the Aramaic language, and everyone translated them as well as he could" (Explanation of the Sayings of the Lord [cited by Eusebius in History of the Church 3:39]).
Sometime after 244 the Scripture scholar Origen wrote, "Among the four Gospels, which are the only indisputable ones in the Church of God under heaven, I have learned by tradition that the first was written by Matthew, who was once a publican, but afterwards an apostle of ************, and
it was prepared for the converts from Judaism and published in the Hebrew language" (Commentaries on Matthew [cited by Eusebius in History of the Church 6:25]).
Eusebius himself declared that "Matthew had begun by preaching to the Hebrews, and when he made up his mind to go to others too,
he committed his own Gospel to writing in his native tongue [Aramaic], so that for those with whom he was no longer present the gap left by his departure was filled by what he wrote" (History of the Church 3:24 [inter 300-325]).
Was Matthew's Gospel first written in Aramaic or Hebrew? | Catholic Answers
Since we don't have an original copy of Matthew in Greek or Aramaic, how can we deny what the church fathers have said about Matthew? I don't think the church Fathers would have any reason to lie about Matthew's Gospel.
As for Paul, he didn't comment on all christian teaching, but he did see Peter as a leader within the Apostles:
"So when James,
Cephas, and John (
who were reputed to be leaders) recognized the grace that had been given me,"
Galatians 2:9 James, Cephas and John, those esteemed as pillars, gave me and Barnabas the right hand of fellowship when they recognized the grace given to me. They agreed that we should go to the Gentiles, and they to the circumcised.
Obviously, Paul saw Peter in a special position:
"I did not go up to Jerusalem to see those who were apostles before I was, but I went into Arabia. Later I returned to Damascus.
18 Then after three years, I went up to Jerusalem
to get acquainted with Cephas[a] and stayed with him fifteen days. 19
I saw none of the other apostles—only James, the Lord’s brother. 20 I assure you before God that what I am writing you is no lie."
Galatians 1:11-24 NIV - Paul Called by God - I want you to - Bible Gateway
So we know Paul saw Peter as a church leader and held Peter in such high regard that he traveled hundreds of miles (probably on foot) to stay with Peter for 15 whole days. Not only that, he stayed with Peter exclusively and didn't stay with any other Apostle.
I think Paul says alot about Peter in both his words and actions.