Srimad Bhagvata Mahapurana: Book 10: Chapter 32: Verses 19-22
Some indeed do not love even those that love them, much less those that do not love them. They are either sages revelling in their own self (and having no knowledge of the external world) or those who have realized their ambition (and are therefore free from all craving for enjoyment, though conscious of external objects) or dullards (who are incapable of appreciating a good turn done to them) or ungrateful people (who bear enmity to their own benefactors that are as good as their father, though conscious of their services). I, for my part, 0 friends, (do not come under any of these categories, being supremely compassionate and friendly, in as much as I) do not (visibly) reciprocate the love (and remain out of sight for some time) of even those individuals who love Me, in order that they could ever think of Me in the same way as a penniless person would, on a treasure found by him being lost, remain engrossed in the thought of that wealth (alone) and would not be sensible to anything else. Indeed in order to ensure thus your constant devotion to Me, 0 fair ones, I remained out of your sight (for some time), though loving you invisibly (and listening to your professions of love with great delight)-you, who have for My sake ignored (all worldly decorum as well as (the injunctions of) the Vedas and deserted your own people. Therefore, 0 beloved ones, you ought not to find fault with Me, your darling. (As a matter of fact) I cannot even through the (long) life of a heavenly being (36000 human years) repay My obligation (which is the duty of all virtuous men) to you, whose connection with Me is (absolutely) free from blemish and who have fixed your mind on Me completely cutting asunder the fetters that bound you to your home and which cannot be easily broken. (Therefore,) let your services to Me be repaid by your own goodness.
Thus ends the thirty-second discourse entitled "The Lord comforts the Gopis during the Rasa- Play° in the first half of Book Ten of the great and glorious Bhagavata-Purana, otherwise known as the Paramahamsa-Samhita.