The transition from an ordinary citizen to a national leader requires a profound internal transformation. This sudden shift in identity is marked by an immediate inner awakening, accompanied by the rapid fulfillment of prophetic promises.
As soon as Saul turned his shoulder to leave Samuel [מצודת ציון, ביאור שטיינזלץ], he experienced a completely new sensation and recognized a changed nature within himself [ביאור שטיינזלץ, אברבנאל]. The timing of this transformation is particularly striking. Samuel had indicated that God would be with Saul only after he encountered a series of three signs, yet this inner shift occurred immediately [אברבנאל, אלשיך]. The change took place precisely at the moment Saul turned his back to the prophet, rather than while they were face to face. This specific timing demonstrated that the new spirit was not transferred from a human mentor, but was bestowed directly by God. This initial awakening served as a preparation, readying his heart to receive the greater prophetic inspiration that would follow [אלשיך].
The nature of this new heart is understood as the sudden presence of royal qualities. It brought a spirit of royal courage [רש״י] and a greatness of character essential for someone destined to rule [מצודת דוד]. While an ordinary person's heart directs only his own individual actions, a king's heart must guide the hearts of an entire nation. Saul's heart was transformed from that of a private individual into the heart of a universal leader, equipped to guide the Israelites and direct their collective will [מלבי״ם].
Following this internal change, the promised events unfolded exactly as foretold. All the signs, particularly the first two which were of a simpler, more earthly nature [אברבנאל], occurred on that very same day without any delay [מלבי״ם].