SB 4.31.19
dayaya sarva-bhutesu
santustya yena kena va
sarvendriyopasantya ca
tusyaty asu janardanah
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
By showing mercy to all living entities, being satisfied somehow or other, and restricting the senses from sense enjoyment, one can very quickly satisfy the Supreme Personality of Godhead, Janardana.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
These are some of the ways in which the Supreme Personality of Godhead can be satisfied by the devotee. The first item mentioned is dayaya sarva-bhutesu, showing mercy to all conditioned souls. The best way to show mercy is to spread Krsna consciousness. The entire world is suffering for want of this knowledge. People should know that the Supreme Personality of Godhead is the original cause of everything. Knowing this, everyone should directly engage in His devotional service. Those who are actually learned, advanced in spiritual understanding, should preach Krsna consciousness all over the world so that people may take to it and make their lives successful.
The word sarva-bhutesu is significant because it applies not only to human beings but to all the living entities appearing in the 8,400,000 species of life. The devotee can do good not only to humanity but to all living entities as well. Everyone can benefit spiritually by the chanting of the Hare Krsna maha-mantra. When the transcendental vibration of Hare Krsna is sounded, even the trees, animals and insects benefit. Thus when one chants the Hare Krsna maha-mantra loudly, he actually shows mercy to all living entities. To spread the Krsna consciousness movement throughout the world, the devotees should be satisfied in all conditions:
narayana-parah sarve
na kutascana bibhyati
svargapavarga-narakesv
api tulyartha-darsinah
(Bhag. 6.17.28)
It does not matter to the pure devotee if he has to go to hell to preach. The Supreme Lord lives in the heart of a hog, although the Lord is in Vaikuntha. Even while preaching in hell, a pure devotee remains a pure devotee by his constant association with the Supreme Personality of Godhead. To attain this state, one has to control his senses. The senses are automatically controlled when one’s mind is engaged in the service of the Lord.