3:12  

इष्टान्भोगान्हि वो देवा दास्यन्ते यज्ञभाविताः ।
तैर्दत्तानप्रदायैभ्यो यो भुङ्क्ते स्तेन एव सः ॥३- १२॥

iShTaanbhogaanhi wo dewaa daasyante yadnyabhaawitaaH ।

tairdattaanapradaayaibhyo yo bhu~Nkte stena ewa saH ॥३- १२॥

Source: Automatic ITRANS Transliteration

Desired pleasures the gods will bestow, nourished by sacrifice.
One who enjoys those gifts without offering to that is but a thief.

The gods, nourished by sacrifice, will bestow desired pleasures. One who enjoys those gifts without offering sacrifice is but a thief.

Source: Milind S. Pandit

The Devas, nourished by Yajna, will give you the desired objects. One who enjoys the gift of the Devas without offering them (anything in return) is, indeed, a thief.

Source: The Bhagavad-Gita: The Sacred Song

In charge of the various necessities of life, the demigods, being satisfied by the performance of yajna [sacrifice], supply all necessities to man. But he who enjoys these gifts, without offering them to the demigods in return, is certainly a thief.

Source: Bhagavad Gita As It Is