Srimad Bhagavatam Canto 10, Chapter 60, Text 02

SB 10.60.2

yas tv etal lilaya visvam
 srjaty atty avatisvarah
sa hi jatah sva-setunam
 gopithaya yadusv ajah
 
Translation: 
 
The unborn Personality of Godhead, the supreme controller, who creates, maintains and then devours this universe simply as His play, took birth among the Yadus to preserve His own laws.
 
Purport: 
 
As stated in the Sixth Canto of the Srimad-Bhagavatam (6.3.19) dharmam tu saksad bhagavat-pranitam: “Religion is the law established by God.” The word setu means a “boundary” or “limit,” as in the case of a dike. Earth is raised up on both sides of a river or canal so that the water will not deviate from its proper path. Similarly, God establishes laws so that people who follow them can peacefully progress along the path back home, back to Godhead. These laws, which are meant to guide human behavior, are thus called setu.
 
A further note on the word setu: Earth that is raised up to separate agricultural fields, or to form a causeway or bridge, is also called setu. Thus in the Ninth Canto the Bhagavatam uses the word setu to indicate the bridge Lord Ramacandra built to Sri Lanka. Since the laws of God act as a bridge to take us from material life to liberated, spiritual life, this additional sense of the word setu certainly enriches its use here.
Srimad Bhagavatam Canto 10, Chapter 60, Text 01
Srimad Bhagavatam Canto 10, Chapter 60, Text 03-06