The Bhagavad Gita with Commentaries of Ramanuja, Madhva, Shankara and Others.
Bhagavad Gita 12.15
http://www.bhagavad-gita.us/articles/200/1/Bhagavad-Gita-1215/Page1.html
By Bhagavan Sri Krishna
 

Text 15

yasman nodvijate loko
lokan nodvijate ca yah
harsamarsa-bhayodvegair
mukto yah sa ca me priyah

Translation

He for whom no one is put into difficulty and who is not disturbed by anyone, who is equipoised in happiness and distress, fear and anxiety, is very dear to Me. 

Commentary by Srila Prabhupada 

A few of a devotee’s qualifications are further being described. No one is put into difficulty, anxiety, fearfulness or dissatisfaction by such a devotee. Since a devotee is kind to everyone, he does not act in such a way as to put others into anxiety. At the same time, if others try to put a devotee into anxiety, he is not disturbed. It is by the grace of the Lord that he is so practiced that he is not disturbed by any outward disturbance. Actually because a devotee is always engrossed in Krishna consciousness and engaged in devotional service, such material circumstances cannot move him. Generally a materialistic person becomes very happy when there is something for his sense gratification and his body, but when he sees that others have something for their sense gratification and he hasn’t, he is sorry and envious. When he is expecting some retaliation from an enemy, he is in a state of fear, and when he cannot successfully execute something he becomes dejected. A devotee who is always transcendental to all these disturbances is very dear to Krishna.

Commentary by Sri Visvanatha Cakravarti Thakur

Moreover, it is said:

yasyasti bhaktir bhagavaty akincana
sarvair gunais tatra samasate surah

One who has unflinching devotion for the Personality of Godhead has all the good qualities of the demigods. SB 5.18.12

By this statement it is understood that also other qualities which please the Lord automatically appear by the constant performance of bhakti to me. Please hear about these. Five verses describe these qualities. The qualities mentioned here-being freed from material jubilation, anger, fear and anxiety - are mentioned again in verse 17 in order to show the difficulty in becoming free from those elements.