What Gautam Buddha said about "self", in Chapter Three of the Mahayana Mahaparinirvana Sutra?

From this site, I found the following saying of Buddha: > "You, monks, should not thus cultivate the  notion (samjna) of impermanence, suffering and non-Self, the notion of impurity and so forth, deeming them to be the true meaning [of the Dharma], as those people [searching in a pool for a radiant gem but foolishly grabbing hold of useless pebbles, mistaken for priceless treasure] did, each thinking that bits of brick, stones, grass and gravel were the jewel. You should train yourselves well in efficacious means. **In every situation, constantly meditate upon [bhavana] the idea [samjna] of the Self, the idea of the Eternal, Bliss, and the Pure** ... Those who, desirous of attaining Reality [tattva], meditatatively cultivate these ideas, namely, the ideas of **the Self [atman], the Eternal, Bliss, and the Pure**, will skilfully bring forth the jewel, just like that wise person [who obtained the genuine, priceless gem, rather than worthless detritus misperceived as the real thing.] > - The Buddha, Chapter Three, "Grief",The Mahayana Mahaparinirvana Sutra Now, as I know this saying is exactly monistic & found in some hindu philosophies like Advait Vedanta & Kashmiri Shaivism. This practice in Advait Vedanta is called *manana*; and in KS, *Shuddha Bhāvna/Vikalpa* under Sāktopāye - Herein you practice not to identify yourself with something (body, mind etc) **which you are not**. In other words I think it seems to teach the same as, > It is not with the body identification that you should sit for meditation. It is the knowledge "I am" that is meditating on itself. > - Nisargadatta Maharaj My question is why Gautam Buddha talked about "self" (that it is eternal, blissful, etc.)? I may not be getting context, so what's the context and explanation?