In the next verse it is explained that devotee will work for Sri Krishna’s enjoyment not for enjoyment for himself. 

Bg 5.10

brahmaṇy ādhāya karmāṇi

saṅgaṁ tyaktvā karoti yaḥ

lipyate na sa pāpena

padma-patram ivāmbhasā

Word for word: 

brahmaṇi — unto the Supreme Personality of Godhead; ādhāya — resigning; karmāṇi — all works; saṅgam — attachment; tyaktvā — giving up; karoti — performs; yaḥ — who; lipyate — is affected; na — never; saḥ — he; pāpena — by sin; padma–patram — a lotus leaf; iva — like; ambhasā — by the water.

Translation: 

One who performs his duty without attachment, surrendering the results unto the Supreme Lord, is unaffected by sinful action, as the lotus leaf is untouched by water.

 

So when the soul offers the karma, to whom? brahmaṇy ādhāya karmāṇi=> ādhāya means to offer, resign to handover so when one does ones karma he thinks this is for the absolute truth.

saṅgaṁ tyaktvā karoti yaḥ => When one gives up attachment and acts 

Such a person lipyate na sa pāpena, such a person doesn’t become bound by karma. Why because such a person is padma-patram ivāmbhasā, -> āmbhasā is water, padma-patra is lotus 

brahmaṇy ādhāya karmāṇi, when we offer the work to the absolute truth, devotee will understand Brahman as Bhagvan so the devotee will offer all his work to Krishna and does all sensory activities for Sri Krishna’s pleasure. The Karma Yogi may not know at this stage that absolute truth is Bhagvan, so Karma Yogi will understand that material nature is acting as Brahman, Brahman can also be used to refer to Material Nature in BG 14.3 & 4 Sri Krishna told Brahman refers to material nature, He says that Sarva Yonis so Kaunteya…where he says that Brhama Yoni su kaunteya…all living beings get their material form within the womb of material nature, Krishna gives the seed. Here Brahma is referred to as the material nature. So when a person doesn’t know about absolute truth he thinks that material nature is acting in this way. So when one thinks this way one doesn’t get oneself emotionally involved in the action of material nature then the person is not bound. E.g. given is padma-patram ivāmbhasā, like water doesn’t stay on lotus leaves. So a devotee who is working in material world can similarly stay detached padma-patram ivāmbhasā if a devotee works in this way brahmaṇy ādhāya karmāṇi.

Srila Prabhupad purport: The Lord also says in the Gītā (3.30), mayi sarvāṇi karmāṇi sannyasya: “Resign all works unto Me [Kṛṣṇa].” 

Give your work to me.

Srila Prabhupada purport: The material world is a sum total manifestation of the three modes of material nature, technically called the pradhāna. The Vedic hymns sarvaṁ hy etad brahma (Māṇḍūkya Upaniṣad 2), tasmād etad brahma nāma rūpam annaṁ ca jāyate (Muṇḍaka Upaniṣad 1.1.9), and, in the Bhagavad-gītā (14.3), mama yonir mahad brahma indicate that everything in the material world is a manifestation of Brahman; Which means including material world is manifestation of Brahman.

This way Sri Krishna is addressing the question of Arjuna how a person who is working in the material world stays free from bondage.