The blessed grave of the Imam becomes fragrant
Ibn Asakar (May Allah shower His Mercy on him) relates in Tareekh Dimashq:
Translation: It is narrated on the authority of Hadhrat ‘Abdullah bin Zahhak (May Allah be well pleased with him), he says: Hisham bin Muhammad (May Allah be well pleased with him) related to us that water was poured over the blessed grave of Imam Hussain (May Allah be well pleased with him). After 40 days, it dried up and there was no sign of the blessed grave. A person from the clan of Asad came, picked up a fistful of sand and started smelling it. Then he fell at the blessed grave of the Imam and started crying...he also recited some couplets, the substance of whom is that when the enemies tried to hide the blessed grave of the Imam, the fragrance of the soil of the blessed grave informed others where the grave is. (Tareekh Dimashq, Li ‘Ali Ibn Al Hasan Ibn Asakar)
It can be understood from the above 2 Traditions that even after the martyrdom of Imam Hussain (May Allah be well pleased with him), benefit and blessings are gained from him. Those who are disrespectful are punished and those who respectful and hopeful of the benevolence of the Imam, they are blessed.