It is narrated from Imam Hussain (AS) who said:
When the soul of a person is saddened because of Ahlul Bait’s (AS) maltreatment; it is Tasbeeh (praise to God, Glory be to God), and the sadness of such person is Ibadah (act of worship) [1].
[1] Beharul Anwaar, Vol. 44, Page 278.
Source: en.shafaqna.com