The Bhagavad Gita with Commentaries of Ramanuja, Madhva, Shankara and Others.
Bhagavad Gita 5.1
http://www.bhagavad-gita.us/articles/464/1/Bhagavad-Gita-51/Page1.html
By Bhagavan Sri Krishna
 

Text 1

arjuna uvaca
sannyasam karmanam krishna
punar yogam ca samsasi
yac chreya etayor ekam
tan me bruhi su-niscitam

Translation

Arjuna said: O Krishna, first of all You ask me to renounce work, and then again You recommend work with devotion. Now will You kindly tell me definitely which of the two is more beneficial? 

Commentary by Srila Prabhupada 

In this Fifth Chapter of the Bhagavad-gita, the Lord says that work in devotional service is better than dry mental speculation. Devotional service is easier than the latter because, being transcendental in nature, it frees one from reaction. In the Second Chapter, preliminary knowledge of the soul and its entanglement in the material body were explained. How to get out of this material encagement by buddhi-yoga, or devotional service, was also explained therein. In the Third Chapter, it was explained that a person who is situated on the platform of knowledge no longer has any duties to perform. And in the Fourth Chapter the Lord told Arjuna that all kinds of sacrificial work culminate in knowledge. However, at the end of the Fourth Chapter, the Lord advised Arjuna to wake up and fight, being situated in perfect knowledge. Therefore, by simultaneously stressing the importance of both work in devotion and inaction in knowledge, Krishna has perplexed Arjuna and confused his determination. Arjuna understands that renunciation in knowledge involves cessation of all kinds of work performed as sense activities. But if one performs work in devotional service, then how is work stopped? In other words, he thinks that sannyasa, or renunciation in knowledge, should be altogether free from all kinds of activity, because work and renunciation appear to him to be incompatible. He appears not to have understood that work in full knowledge is nonreactive and is therefore the same as inaction. He inquires, therefore, whether he should cease work altogether or work with full knowledge.

Commentary by Sri Visvanatha Cakravarti Thakur

Having spoken of karma as superior to jnana, in order to strengthen this idea in this chapter, jnana is said to be equivalent to karma.

Being worried about the contradiction of the two statements at the end of the previous chapter, he asks a question.

In verse 41 of the last chapter you spoke of renouncing karma by jnana arising from karma yoga (yoga-sannyasta-karmanam) but in verse 42 you again spoke of taking up karma yoga (yogam atisthottistha bharata).

It is not possible to perform both renunciation of action and karma yoga at once because there is essential contradiction of the two as there is contradiction in remaining stationary and moving. Therefore the man of knowledge should either renounce karma or perform karma yoga. As I do not understand your intention, I am asking. Among these two, which one is better? Please tell that definitely to me.