The summers had become unbearable because of the drought. No relief was visible. The people of Medina were found often staring at the sky, in the hope of spying some clouds, but were always disappointed. The scarcity of food and water was giving the Medinites a hard time.
To top it all, reliable sources informed the Holy Prophet (s) of an invasion by the Romans. The large Roman army was seen forging ahead towards Syria in the north eastern part of the Islamic state, and it was a power to be dealt with. The Holy Prophet (s) announced plans to meet them near Syria and told all the Muslims to prepare for war. They would set out immediately.
The Muslims, exhausted by the climatic conditions, agreed with no great zeal. The hypocrites made all kinds of excuses to be relieved of participation, hoping to enjoy the harvest season with its wealth of fruit and grain. However, no one was granted relief, and they all set out with their meagre supplies of food and water. There were fears that they would run out of supplies before reaching Syria, and that thought did no good to those already unwilling to engage in war at that time.
The thirty thousand Muslims trudged on in the merciless heat. On the way, some Muslims of weak faith started returning to Medina. Suddenly, some companions noticed Kaab ibn e Maalik turn his horse and trot homewards. They informed the Holy Prophet (s) of his departure. The Holy Prophet (s) wasn’t upset. He just said, wasn’t upset. He just said, wasn’t upset. He just said,
‘Let him go. If there is an iota of good in him, God will send him back to you. If he doesn’t return, be convinced that God has saved you from his evil-intentions.’ A few minutes later they cried, ‘Kararah ibn e Rabei has also left us, Ya Rasool Allah!’
‘Let him go. If there is an iota of good in him, God will send him back to you. If he doesn’t return, be convinced that God has saved you from his evil-intentions.’ A few minutes later, they cried, ‘Hilal ibn e Ummayya has also left.’ The Holy Prophet (s) repeated the same words.
Meanwhile, Abu Dharr’s camel suddenly stood still and refused to move. He desperately tried to urge it on, but to no avail. Not wishing to be left too far behind, he gathered his things and started on foot. On the way, the heat and the weight he was carrying drained him of all energy. He felt he could not go any further, but refused to give up. Suddenly, his foot struck against a rock. He looked and found a pool of fresh rain water. Looking up he saw some clouds moving away. He just tasted the water, and finding it palatable, filled his leather water bag with it. He was anxious to reach the rest of the army, so he walked faster, even though the weight on his back had increased considerably. However, faith was his guiding power and he did not lose heart.
The companions of the Prophet (s) made another announcement. ‘Abu Dharr cannot be seen. He seems to have also left, Ya Rasool Allah!’ The Holy Prophet (s) sighed, and repeated the same words once more.
The path being rough and uneven, Abu Dharr’s mouth was absolutely parched, but he saw the rear end of the army, and filled with joy, started running towards them. The people at the rear end saw somebody trying his best to reach them. They stopped and announced, ’One of them is coming back, Ya Rasool Allah!’ ‘Dear Lord, let it be Abu Dharr.’
‘It is Abu Dharr, it is Abu Dharr!’ they cried in unison. ‘Forgive him, my Lord, he is unparalleled in truthfulness,’ prayed the Holy Prophet (s). Abu Dharr reached the Holy Prophet (s), who had covered part of the distance between them, and collapsed at his (s) feet.
‘Bring some water,’ ordered the Holy Prophet (s). ‘I have water with me, Ya Rasool Allah,’ gasped Abu Dharr. ‘Why did you not drink it and quench your thirst, Abu Dharr?’
‘May my parents be accepted as ransom for you, Ya Rasool Allah. I struck a rock on the way and found fresh water behind it. When I tasted it and found it good, I thought of you, and vowed to drink it only after you had quenched your thirst with it.’
Reference : Anecdotes of The Ahlul Bayt (Daastaan e Raastaan ) by Ayatullah Murtadha Mutahhari