Eleventh ground? What basis can you say that there is an eleventh ground ie beyond the tenth. Do you mean that of a Buddha ie beyond the tenth?
Right. The tenth bodhisattva ground, known as “Cloud of Dharma”, is still included in the continuum of a sentient being, while the eleventh ground, known as the “Omnipresent Light”, is the ground of a buddha.
This explanation is offered by Yangchen Gawai Lodoe, or Akya Yongzin, a famous 18th century Gelugpa teacher, citing the great Indian pandita Abhayakaragupta (see
Path and Grounds of Guhyasamaja According to Arya Nagarjuna, LTWA, p. 117)
Also the emanation of the 5 bodies of the "attained Lama" correspond to the 5 Dhayani Buddhas, that is not to say that the 5 Budddhas actually emanated into that of the Lama; but the qualities of the 5 Dhayani Buddhas are what these emanations represent. Each encapsulate the others but the particular qualities is more prevalent to the observer.
While the 5 Buddha-Families teaching is firmly based on the authority of Buddhist Tantras, the idea that “attained lamas” emanate 5 bodies corresponding to body, speech, mind, qualities, and activity, to my knowledge, is not. I have never heard of such 5 emanations nor in reference to the great Indian panditas and mahasiddhas, nor in reference to Tibetan Gelugpa lamas.
Indeed, such 5 bodily emanations of “attained lamas” are usually mentioned in reference to Bönpo lamas, and also within the heavily Bön-influenced Nyingmapa tradition, or other heavily Nyingma-influenced Buddhist traditions. Therefore, it is just reasonable to suspect that this might be rather a non-Buddhist, Bön-originated belief, imported into Buddhism.
Anyway, let's not forget the theocratic and feudal nature of old Tibetan society, and therefore the need felt by the noble, powerful, rich, land-owning families to assert and perpetuate their tyrannical authority over the masses of servants, slaves, and other destitute people.
In such context, multiplying 5 times the spiritual authority of each deceased “attained lama”, and distributing it among 5 noble scions, even the less spiritually inclined, thus awarding all of them the power and authority of some divine status, comes in pretty handy indeed.
Therefore, the likely lack of Buddhist scriptural authority, combined with the obvious political expediency of the 5 “attained lama” emanations theory in a theocratic-feudal context suggests that one should be at least careful before swallowing it as an authentic Buddhist teaching.