It is narrated from Imam Sadeq (AS) who said: The day of the martyrdom of Imam Hussain (AS) is the most heart breaking day because the Companions of Kasa, who are the most honourable human beings created by Allah (SWT) are five, when Imam Hussain (AS) was martyred, none of the Companions of Kasa remained to be bring comfort and consolation to people. Therefore, when Imam Hussain (AS) went is the same as all five of them went, the same as when Imam Hussain (AS) was alive, it was like all the Companions of Kasa were alive [1].
[1] Elalul Sharaye’a, Vol. 1, Page 225.
source : shafaqna