I'll be quoting from Alister McGrath's book In The Beginning
"Middle English did not know the word 'its,' meaning 'belonging to it.' In its place, Middle English used the word 'his.' This word could mean one of two things: 'belonging to him,' and 'belonging to it.' By 1600, however, the word 'his' was increasingly being used solely as the masculine possessive pronoun. Yet the same word was still used, even if increasingly rarely, to act as the neuter possessive pronoun. Even though 'its' was unquestionably gaining the upper hand, it had yet to achieve dominance. This is reflected in the King James Bible, which uses the term 'its' only once, at Leviticus 25:5." (p.274)