John 21:18
Verily, verily, I say unto thee, When thou wast young, thou girdedst thyself, and walkedst whither thou wouldest: but when thou shalt be old, thou shalt stretch forth thy hands, and another shall gird thee, and carry thee whither thou wouldest not.
Cross-references
John 13:36
Prophetic fulfillment
John 13:36 promised Peter would follow Jesus later; here Jesus specifies that later death by stretching out his hands.
2 Peter 1:14
Citation
In 2 Peter 1:14, Peter explicitly references Jesus' prediction of his death — the same prophecy given in John 21:18.