Bhagavad Gita: Chapter 5, Verse 13

BG 5.13: The embodied beings who are self-controlled and detached reside happily in the city of nine gates free from thoughts that they are the doers or the cause of anything.

Shree Krishna compares the body with its openings to a city of nine gates.  The soul is like the king of the city, whose administration is carried out by the ministry of the ego, intellect, mind, senses, and life-energy.  The reign over the body continues until time, in the form of death, snatches away the corporeal frame.  However, even while the reign continues, the enlightened yogis do not see themselves as the body nor do they consider themselves as the lord of the body.  Rather, they hold the body and all activities performed by it as belonging to God.  Renouncing all actions through the mind, such enlightened souls remain happily situated in their body.  This is also called sākṣhī bhāv, or the attitude of being the detached observer of all that is happening around. 

The analogy in this verse is also given in the Śhwetāśhvatar Upaniṣhad:

navadwāre pure dehī hanso lelāyate bahiḥ
vaśhī sarvasya lokasya sthāvarasya charasya cha   (3.18)

“The body consists of nine gates—two ears, one mouth, two nostrils, two eyes, anus, and genitals.  In material consciousness, the soul residing with the body identifies itself with this city of nine gates.  Within this body also sits the Supreme Lord, who is the controller of all living beings in the world.  When the soul establishes its connection with the Lord, it becomes free like Him, even while residing in the body.”

In this verse, Shree Krishna declared that the embodied soul is neither the doer nor the cause of anything.  Then the question arises whether God is the actual cause of actions in the world.  This is answered in the next verse.