Short answer: We do not know exactly.
We do know that on July 2 he was at home in Greenwich writing his will in preparation for leaving home to join the army as a chaplain. (His personal estate, all willed to Betsy, included a 5 volume collection of John Witherspoon’s works, an eight-volume set of the Spectator, his watch, and his horse, Bullrock). One week later he was in Philadelphia with his regiment preparing to depart for what would soon become the Battle of Long Island. While in Philadelphia, Philip wrote home to Betsy: “Several Companies go out of Town this day for New Jersey, in which this Day shows: Suffice it to say, all are in Arms.”