SB 9.11.20

nedaṁ yaśo raghupateḥ sura-yācñayātta-
 līlā-tanor adhika-sāmya-vimukta-dhāmnaḥ
rakṣo-vadho jaladhi-bandhanam astra-pūgaiḥ
 kiṁ tasya śatru-hanane kapayaḥ sahāyāḥ
Synonyms: 
na — not; idam — all these; yaśaḥ — fame; raghu-pateḥ — of Lord Rāmacandra; sura-yācñayā — by the prayers of the demigods; ātta-līlā-tanoḥ — whose spiritual body is always engaged in various pastimes; adhika-sāmya-vimukta-dhāmnaḥ — no one is greater than or equal to Him; rakṣaḥ-vadhaḥ — killing the Rākṣasa (Rāvaṇa); jaladhi-bandhanam — bridging the ocean; astra-pūgaiḥ — with bow and arrows; kim — whether; tasya — His; śatru-hanane — in killing the enemies; kapayaḥ — the monkeys; sahāyāḥ — assistants.
Translation: 
Lord Rāmacandra’s reputation for having killed Rāvaṇa with showers of arrows at the request of the demigods and for having built a bridge over the ocean does not constitute the factual glory of the Supreme Personality of Godhead Lord Rāmacandra, whose spiritual body is always engaged in various pastimes. Lord Rāmacandra has no equal or superior, and therefore He had no need to take help from the monkeys to gain victory over Rāvaṇa.
Purport: 

As stated in the Vedas (Śvetāśvatara Upaniṣad 6.8):

na tasya kāryaṁ karaṇaṁ ca vidyate
 na tat-samaś cābhyadhikaś ca dṛśyate
parāsya śaktir vividhaiva śrūyate
 svābhāvikī jñāna-bala-kriyā ca

“The Supreme Lord has nothing to do, and no one is found to be equal to or greater than Him, for everything is done naturally and systematically by His multifarious energies.” The Lord has nothing to do (na tasya kāryaṁ karaṇaṁ ca vidyate); whatever He does is His pastime. The Lord has no duty to perform to oblige anyone. Nonetheless, He appears to act to protect His devotees or kill His enemies. Of course, no one can be the Lord’s enemy, since who could be more powerful than the Lord? There is actually no question of anyone’s being His enemy, but when the Lord wants to take pleasure in pastimes, He comes down to this material world and acts like a human being, thus showing His wonderful, glorious activities to please the devotees. His devotees always want to see the Lord victorious in varied activities, and therefore, to please Himself and them, the Lord sometimes agrees to act as a human being and perform wonderful, uncommon pastimes for the satisfaction of the devotees.