From here: http://gospel-of-matthew.co.tv/#cite_note-carson-moo_8
Matthew was also said to have written the very first Gospel [66] [67] [68] in Hebrew near Jerusalem for Hebrew Christians and it was translated into Greek, but the Greek copy was lost. The Hebrew original was kept at the Library of Caesarea. The Nazarene Community transcribed a copy for Jerome http://books.google.ca/books?id=Cb4CAAAAQAAJ&pg=PA82&dq=Matthew+Jerome+%22The+Fathers+of+the+Church%22+%22+Gospel+according+to+the+Hebrews%22++extant&num=100#v=onepage&q=Matthew%20Jerome%20%22The%20Fathers%20of%20the%20Church%22%20%22%20Gospel%20according%20to%20the%20Hebrews%22%20extant&f=false which he used in his work. [69] Matthew's Gospel was called the Gospel according to the Hebrews http://books.google.ca/books?id=_wLZAAAAMAAJ&q=Hebrew+%22Gospel+of+matthew%22+%22in+the+New+Testament+expounded+and+declared+the+gospel+in+Hebrew+%22+%22Gospel+according+to+the+Hebrews+%22+Cerinthus+Merinthus,&dq=Hebrew+%22Gospel+of+matthew%22+%22in+the+New+Testament+expounded+and+declared+the+gospel+in+Hebrew+%22+%22Gospel+according+to+the+Hebrews+%22+Cerinthus+Merinthus or sometimes the Gospel of the Apostles [70] [71] and it was once believed that it was the original to the Greek Matthew found in the Bible, although this is currently disputed by modern Biblical Scholars. [8]