Now be very clear that while the ten Bhumis or Grounds are evaluative, the idea is not to generate the egoist evaluation "oh, I am at the third Bhumi," or any other. It is to help you see where you stand and what you should be doing to direct yourself better. They should be always linked to the Avaivartika path and the Bodhicharyavatara.
It is at best a guide to the perfect advancrement but that is all
It is called "very joyous" because the bodhisattva experiences that state when working on the perfections of generosity and is on the path developing the ability to give away all attachments of mind or body without regret and with no thought of praise or reward.
The First bhūmi, called the "Very Joyous", is attained with the first direct cognitive experience of emptiness and is simultaneous with entry into the third of the five paths to awakening, the path of seeing.
Now the emptiness which is comprehended here is not that attained when pursuing the Emptiness of Emptiness itself, but the consequence of simply dwelling in meditation within conceptual emptiness and carrying that experience into every day affairs.
All phenomena are then viewed as empty and as subject to decay, suffering, and the ending of apparent existence, and so bodhisattvas lose eventually all attachment to them.
That means, in simple terms, that as a result of the basic meditation upon emptiness, not the more advanced Emptiness of Emptiness itself, they are conscious of any moments of habitual clinging and craving and release such attachments.
Due to this, they overcome the false idea that the five aggregates constitute a truly existent person. In other words they sense, although cognitively directed, that there really is no self. However, they do understand that this illusion, if not stained by Identity, is a valid truth.
They also eliminate predispositions toward corrupted VIRTUE so completely, that they will not arise again. In other words, they reject social values and look to a deeper fount of natural virtue.
Despite having directly dwelt within emptiness, Bodhisattvas on the first level are primarily motivated by confidence and not, as many suppose, by blind faith. They develop virtue on the basis of a cognitive impulse, in order to cleanse their minds of negativity so that they prepare themselves for the cultivation of mundane meditative absorption that comes on the second level.
In summary, we can say that the Bodhisattva has dwelt in meditation with emptiness and that while dwelling in the presence of the experience of the emptiness of all things, has cut the predisposition for attachment. Then, since he has also the cut initial bonds of Identity, he becomes other-directed. Consciously he then continues to develop the perfection of GENEROSITY until consequently this practice generates a natural GENEROSITY.