In plain words
The reason is that the thorns have not entered it. The branches and leaves have not entered it. Since it has put away the branches, leaves and thorns, it stays perfectly pure. For all the time that feelings bound up with the objects of the senses are in us, this can only be called lust. By putting them away it can be called love. This Prema, too, must be wide Prema. This itself is expansion love. To try to enjoy this Prema only for one's own self-interest, for the sake of one's own wishes, is a kind of selfish, contrived, narrow contraction, a lesser Prema. The Upaniṣads, the sacred Purāṇas and the Itihāsas help us greatly to make the fitting effort to widen this selfish one into a sacred Prema for others. Today you who are young, through the Prema you have gathered in so many ways, fall into so many kinds of trouble, simply lose your steadiness, nurse only a delusion, and through that delusion set about putting away the very goal of your life. So, to purify this Prema, you must join satsaṅga, listen to what sacred elders have said, put at least one or two of those things into practice, render fitting service to your mother and father at home, satisfy them, make them glad, and then go forward to the goal of your life and stand ready to bring the country the security it needs. For this you must practise the sādhanas fit for shaping the intellect into a mirror and making it pure. You can see the form of your humanity only in the mirror called citta and intellect; you cannot see it anywhere else. When this intellect is pure, our attachment too takes the form of an attachment free of selfishness. Only when you believe that the whole world is your mansion and regard all the beings dwelling in the mansion as parts of you is there the chance for you to develop, to some extent, a wide feeling and a wide Prema.