On Muharram 9th, 61 A.H. Umar bin Saad started his attack at night. He advanced towards Imam Husayn's camp. Zaynab, Imam Ali's daughter, heard the enemy's voice. She said to her brother al-Husayn:
The enemies have approached!
Imam Husayn [a] ordered his brother al-Abbas to ask them. Al-Abbas, Habib bin Muzahair, and twenty persons jumped on their horses and rode away. Al-Abbas asked them about their aim. They said:
Obey Ubaidullah bin Ziyad, otherwise we'll attack you!
Al-Abbas came back to Imam Husayn [a] to tell him about the enemy's attitude.
Habib stayed behind. He began advising the enemy army:
By Allah, tomorrow, Allah will regard you as bad people! How will you meet Him while you are going to kill Imam Husayn and his family? Don't you know that they're the Prophet's grandsons? Don't you know that they pray to Allah after midnight and remember Him very much?
An enemy person called Uzrah said:
Habib, you're praising yourself!
Allah has praised and guided him. Uzrah I advise you to fear Allah!