Who was the first person to "Fast" in the Bible?

The first person I can find in the Bible that is said to be fasting is David (2 Samuel 12:21-23 [21] Then said his servants unto him, What thing is this that thou hast done? thou didst fast and weep for the child, while it was alive; but when the child was dead, thou didst rise and eat bread. [22] And he said, While the child was yet alive, I fasted and wept: for I said, Who can tell whether GOD will be gracious to me, that the child may live? [23] But now he is dead, wherefore should I fast? can I bring him back again? I shall go to him, but he shall not return to me.
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However, most Jewish and Christian teachers believe the the command to the Israelites to "afflict your souls" (Leviticus 16:29And this shall be a statute for ever unto you: that in the seventh month, on the tenth day of the month, ye shall afflict your souls, and do no work at all, whether it be one of your own country, or a stranger that sojourneth among you:
See All...; Leviticus 23:27Also on the tenth day of this seventh month there shall be a day of atonement: it shall be an holy convocation unto you; and ye shall afflict your souls, and offer an offering made by fire unto the LORD.
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"Wherefore have we fasted, say they, and thou seest not? wherefore have we afflicted our soul, and thou takest no knowledge? Behold, in the day of your fast ye find pleasure, and exact all your labours."

This being the case, it is almost certain that the Jews fasted once a year on the day of atonement long before we read of David fasting.