Once Bayazid Bustami (a renowned pious individual) was going on a journey when a Christian accompanied him along. When it was time for mid-day meal, Bayazid suggested to his companion that he should go to the village at hand and have food. The Christian said, "No, Bayazid you are a godly person. Pray to God that He may furnish the food here."
Bayazid offered two units of Nawafil in prayer and begged of Allah, "My Lord! This man wants to test my religion. Please, protect its good name so that I may not be put to shame. Kindly arrange for our food." He had hardly finished his prayer when a person appeared with four loaves of bread and some curry. Both of them ate to their fill and resumed their journey.
In the evening the Christian companion said that he would arrange for the supper. He also reaised his hands in prayers and at once appeared a man with eight loaves of bread and double quantity of curry. Bayazid was wonder-struck and asked him what he had prayed for. The Christian replied that first he should be converted to Islam and then he would disclose the detail of the prayer. At this, Bayazid converted him to Islam.
The companion related that he had prayed like this: "O Lord! If Islam is a true religion and you are kind to Bayazid, provide us with the double quantity of food that we had at midday. So the response to my prayer is obvious."
Source: Extracted from the book "From Darkness to Light" written by Prof. Gazi Ahmed who was converted to Islam from Hinduism by Prophet Muhammad (SAW) through several dreams.