Here are three very short stories, told by three different people, that demonstrate the unselfish and generous nature of the Prophet Joseph Smith.
John E. Page:

At the time Brother Page was called to go on a mission to Canada, he objected, for the reason that he was destitute of clothing. Brother Joseph Smith took off his coat and gave it to him, and told him to go, and the Lord would bless him abundantly on his mission.
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“History of John E. Page,” Latter-day Saints’ Millennial Star 27, no. 7 (18 February 1865): 103.
Andrew Workman:

. . . I knew him as soon as I saw him. Although I was young I knew him to be a man of God. A few days after this I was at Joseph’s house; he was there, and several men were sitting on the fence. Joseph came out and spoke to us all. Pretty soon a man came up and said that a poor brother who lived out some distance from town had had his house burned down the night before. Nearly all of the men said they felt sorry for the man. Joseph put his hand in his pocket, took out five dollars and said, “I feel sorry for this brother to the amount of five dollars; how much do you feel sorry?”
Andrew Workman, “Recollections of the Prophet Joseph Smith,” Juvenile Instructor 27, no. 20 (15 October 1892): 641; Mark L. McConkie, Remembering Joseph, 60.
Joseph Knight Sr.:

One day the Prophet saw his elderly friend hobbling along without a cane. The Prophet approached him and, putting his arm around him, pressed Father Knight’s fingers onto the top of his cane and said, “Brother Knight, you need this cane more than I do.” The Prophet then told him to keep it as long as he needed it, and then to pass it on to descendants with the first name Joseph. The cane has been passed down through several descendants until the present day.
Susan Easton Black, Who’s Who in the Doctrine and Covenants (Salt Lake City, Utah: Deseret Book, 1997), 167; Mark L. McConkie, Remembering Joseph, 56.