Volume 4, Book 52, Number 60:
Narrated Abdullah bin Abbas:
That Abu Sufyan told him that Heraclius said to him, “I asked you about the outcome of your
battles with him (i.e. the Prophet ) and you told me that you fought each other with alternate success.
So the Apostles are tested in this way but the ultimate victory is always theirs.
Volume 4 – 647 / 1700
SAHIH BUKHARI VOLUME 4 > BOOK 52: FIGHTING FOR THE CAUSE OF ALLAH (JIHAAD)