Sahih Bukhari
Volume 4, Book 52, Number 148 :
Narrated Salama bin Al-Akwa :
The Prophet ﷺ passed by some people of the tribe of Bani Aslam who were practicing archery.
The Prophet ﷺ said, “O Bani Ismail ! Practice archery as your father Isma’il was a great archer. Keep on throwing arrows and I am with Bani so-and-so.” So one of the parties ceased throwing.
Allah’s Apostle ﷺ said, “Why do you not throw?” They replied, “How should we throw while you are with them (i.e. on their side)?” On that the Prophet ﷺ said, “Throw, and I am with all of you.”