Adolf Von Harnack mentions a tradition that the Apostles spent twelve years in Jerusalem after the Ascension based on a command from Jesus. He writes:
…for in the Acta Petri cum Simone, 5, and in Apollonius (in Eus. H.E., v.18.14), the word (here also a word of the Lord) runs that the apostles were to remain for twelve years at Jerusalem, without any mention of the exodus …. Twelve (or eleven) years after the resurrection is a period which is also fixed by other sources (see von Dobschutz in Texte u. Unters., XI.i. p.53 f.); indeed it underlies the later calculation of the year when Peter died (30+12+25=67 A.D.).
Von Harnack was referencing The Acts of Peter, an apocryphal book, which says:
V. And as they prayed and fasted, God was already teaching Peter at Jerusalem of that which should come to pass. For whereas the twelve years which the Lord Christ had enjoined upon him were fulfilled, he showed him a vision after this manner, saying unto him…
This tradition is also mentioned by Eusebius in his Church History V.18.14:
He [Apollonius] speaks, moreover, of a tradition that the Savior commanded his apostles not to depart from Jerusalem for twelve years. He uses testimonies also from the Revelation of John, and he relates that a dead man had, through the Divine power, been raised by John himself in Ephesus. He also adds other things by which he fully and abundantly exposes the error of the heresy of which we have been speaking. These are the matters recorded by Apollonius.