The Arab infidels, Jews and others, two hundred people gathered in Hajj season in Mecca and decided to eliminate His Eminence (S) and set out to Medina Munawwara with this aim.
On the way, they halted at a place where they found a pond having water which was more clear and fragrant than the water they carried with them. So they threw away the water they were carrying and filled their water skins with that water and set out from there. After sometime, they halted at a place where there were many rats. Allah imposed the rats on them and they chewed up the water skins and all the water leaked out in the rocky area and they knew nothing about it.
When they became thirsty, they found that there no water in their skins. They returned to the pond from which they had filled water but the rats had reached there first and made holes in the edges of the pond spilling all the water in the rocky ground. They despaired of finding water and perished in thirst. Only one survived and he was writing the name of Muhammad (S), on his tongue and stomach and saying: O Allah, I repent for my wrong deed.
For the sake of the status of Muhammad (S) remove this trouble from me. Thus he remained alive and Allah quenched his thirst. A caravan was passing by, which picked him up with the belongings of the dead along with their camels. And he was more patient in thirst than his she-camels. Then he came to Medina and accepted faith at the hands of the Prophet. His Eminence (S) gave all the camels and goods of the dead people to him.
Reference:Hayat Al-Qulub Vol. 2