Rubaab had two children, Sakina and Ali Asghar. She and her two children accompanied Imaam to Kerbala. The fact that Imaam took with him a newly born baby further demonstrates the that his intention was never to engage in any armed rebellion.
At Kerbala Asghar was only six months old. From the seventh Muharram there was no water in Imaam's camp. Asghar was in great pain because of thirst.
On Ashura day, after Ali Akber had been killed, Imaam Hussain was standing outside the camp. He was left all alone and he was preparing to go into the battlefield. Just then he heard a child cry. It was Ali Asghar, tormented by the pangs of hunger and thirst.
Imaam walked into Bibi Rubaab's tent. He lifted the child from the cradle. "Rubaab," he said, "I will take him to Yazeed's army. Surely they can not possibly deny this little infant a few drops of water?" Rubaab changed Ali Asghar's clothes. She even tied a small turban on his head. Like any other mother she wanted her son to look at his best in front of strangers.
Imaam Hussain carried the child to the battle field. Walking up to Yazeed's soldiers Imaam Hussain said, "This child has done you no harm. He is dying of thirst. I am begging for a few drops of water for him."There was no response. Imaam said, "If you are afraid that when you bring Asghar any water I will drink it, look, I will put him on the ground and you can come yourself and give him water." He put the child on the sands of Kerbala and moved a couple of steps back.You can imagine how hot the desert sand was. Asghar lay there not even wincing. He turned towards the enemy and stared at them. A murmur arose among the soldiers but no one came forward to give water to the baby. Imaam took Asghar in his arms and in a clear voice said, "Asghar, my son, show them how thirsty you are!" Asghar turned his head towards the soldiers. He smiled sweetly. Opened his mouth. Brought out his dry tongue and moved it over his lips. The ultimate sword had been unsheathed !
The soldiers were so moved by this that they could be heard sobbing. Still, they were very afraid of Yazeed and none dared come forward to give water to Ali Asghar.
Umar Sa'ad was worried. It seemed that Asghar was emerging victorious in this confrontation against the might of Yezid. He looked at Hurmala, a famous archer, and said, "Silence Hussain!"
Then a terrible thing happened. Hurmala lifted his bow. Aimed an arrow at the child. The arrow flew across the hot desert. There was a hissing sound. Asghar smiled. He lifted his head and arched his neck!! No civilized mind can even imagine what happened next. The hissing sound stopped and Asghar lay still on his father's arms.
Imaam Hussain looked down at Asghar's neck, he saw the arrow, he saw the neck, he saw the smile and then he could see no more!!!
Our Imaam began to feel faint. For a moment everything went dark. He could not see! There was a total silence over Kerbala, broken only by the sound of the gentle waves of Furaat. Even the enemy appeared stunned.
Slowly Hussain turned round and now looked at the baby in his arms.
The arrow had passed through the tender neck and lodged in Imaam Hussain's chest. There was no way Imaam Hussain could dislodge the arrow. His two arms were supporting the still child. He looked at the sky, and prayed "Ya Allah, give me courage in this most difficult moment of my life. No Prophet ever was subjected to a test as severe as this."
It is said that the Imaam was so shaken up by what had happened to the infant child, that all of a sudden his beard went all grey and he looked an old man. With his teeth he pulled his abaa over Asghar to shield the body from the scorching sun. Then he took a few deep breaths, and began to walk towards his camp.
As he got near he saw Rubaab standing at the entrance to her tent. He saw the anxiety, the hope, the fear and the restlessness in her eyes. Our Imaam seemed to lose all strength. He could not walk forward towards Bibi Rubaab. He took seven steps back saying "INNA LILLA-HI WA INNA ILAY-HI RAJEEOON". He stopped and thought that he must take the child to his mother. He again took seven steps forwards saying "INNA LILLA-HI WA INNA ILAY-HI RAJEEOON". Once again his eyes met with those of Bibi Rubaab's. Again our Imaam seemed to lose his courage and walked backwards repeating "INNA LILLA-HI WA INNA ILAY-HI RAJEEOON". Imaam Hussain did this seven times. Forward and backward. All the time Bibi Rubaab's eyes remained transfixed on the child. Each time Imaam reciting "INNA LILLA-HI WA INNA ILAY-HI RAJEEOON".
Finally, somehow, he got the arrow dislodged. He now took the dead infant to Bibi Rubaab. He said, "Rubaab! This is a test from Allah which no mother has ever been asked to go through. Come with me" Bibi Rubaab followed. With their own hands they dug a small grave! The father and the mother together buried Ali Asghar!!