'One's' in the Bible

“For the Lord has called you,Like a wife forsaken and grieved in spirit,Even like a wife of one’s youth when she is rejected,”Says your God.

“Is it a fast like this which I choose, a day for a man to humble himself?Is it for bowing one’s head like a reedAnd for spreading out sackcloth and ashes as a bed?Will you call this a fast, even an acceptable day to the Lord?