Sahih Bukhari
Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi)
Volume: 005 / Book Number: 059 / Hadith Number: 436
Narrated Sulaiman bin Surd:
When the clans were driven away, I heard the Prophet saying, "From now onwards we will go to attack them (i.e. the infidels) and they will not come to attack us, but we will go to them."