awliyah

They have purified their hearts from other than Allah and they have made them as pathways for rivers to run, receiving knowledge of the Divine Presence.
— 

Imam Ghazali said in the honour of Awliya (Friends of Allah), al-Munqidh min ad-Dalal, page 131

The hearts of the Awliya have been cleansed to such an extent that they are able to receive exclusive knowledge of the Creator.