Imaam Ibnul Qayyim (rahimahullaah) said:
The heart has six places of residence in which it roams about and there is not a seventh one for it; three lowly ones and three lofty ones. The three lowly ones are:  Adornment of the worldly life for it;  a Nafs that makes suggestions to it;  the enemy that whispers to it (i.e. Shaytaan). These are the places of residence of the lowly souls in which they do not cease to roam about. And the three lofty (places of residence are):  knowledge that makes things clear for it;  intellect that guides it;  and a God it worships (i.e. Allaah). The hearts roam about in these places.
[Source: Al-Fawaa-id: page: 156]