One of the basic Sufi practices to open the heart is remembrance. Abu-Hamid al-Ghazali, in his book Invocations and Supplications, notes that remembrance has four basic meanings. First, it is an act of constantly striving to be mindful of God. In this sense, it is the opposite of heedlessness. Prayer is also remembrance. Prayer invites the Sufi into God's presence.
— James Fadiman, Robert Frager, Essential Sufism by James Fadiman, editor, Robert Frager, editor