In plain words
A merchant who sells laḍḍus and sweets sits right in his own shop. All those smells keep reaching his nose. The sweets are there before his eyes. But he has no liking for them at all. He sends for puffed rice from the shop next door and eats it with great relish. Truly, this applies to everyone in the world. People do not relish the food cooked in their own homes. The food of other people's houses, though, seems very tasty. But that is not the reason Kṛṣṇa took the butter of other people's houses. Butter means the pure heart itself! Wherever such a pure heart is, there Kṛṣṇa goes and accepts it.
The Gopīs' hearts were ripe. Ripe hearts are soft and sweet. That is why He kept stealing their hearts. But that theft, for its part, brought Kṛṣṇa a bad name. Everyone went on calling Kṛṣṇa ‘Thief, thief’. If we call anyone ‘Thief!’ for no reason, they get angry. If we put that same word into a song and sing ‘Thief of hearts!’, everyone sways their heads in delight. When it is joined to song, it is very sweet. However you call Him with Prema, it is sweet to God all the same. Otherwise, why would everyone call Him ‘Thief of hearts!’? “Thief of hearts, Yaśodā's child! Gopāl, thief of butter! Gopāl, Gopāl, Gopāl, Gopāl who held up Govardhana!” You yourselves can think how sweet a song is that joins feeling, melody and rhythm in this way. If you call out ‘Hey, thief! Come here’ without such feeling, melody and rhythm, anyone at all will flare up in anger. Devotees such as Tyāgarāja offered God sweet singing full of feeling, melody and rhythm, and they gained a sweet feeling themselves. If you want to attain God, you cannot attain Him with mere words. Only when feeling, melody and rhythm come together does it go straight to God's heart. So, through soft and sweet singing we can attain God.