Means of Softening the Heart – Ibn Rajab
The heart’s softness grows due to remembrance (of Allaah), for indeed remembrance of Allaah makes the heart (submissive , tranquil and attentive), upright and soft.
Lataa’if Al-Ma’aarif ‘ page 46’ by Imaam Ibn Rajab Al-Hanbali ( rahimahallaah )