Speech of heart.

Source: http://www.ashrafiya.com/

It is an established principle that when the tongue is busy talking the heart is quietly listening to it. Whereas, when the tongue is silent the heart starts to talk.

Therefore, hold your tongue so that the heart does not listen to its useless speech. Instead make it the organ of remembrance (of Allah). Hence, your heart will become accustomed to this remembrance. (And eventually start to speak this itself).

And tawfiq is from Allah!

Ma’arif e Sufiya, page 334