'Appointed' in the Bible

Adam knew [Eve as] his wife again; and she gave birth to a son, and named him Seth, for [she said], “God has granted another child for me in place of Abel, because Cain killed him.”

Is anything too difficult or too wonderful for the Lord? At the appointed time, when the season [for her delivery] comes, I will return to you and Sarah will have a son.”

now let it be that the girl to whom I say, ‘Please, let down your jar so that I may [have a] drink,’ and she replies, ‘Drink, and I will also give your camels water to drink’—may she be the one whom You have selected [as a wife] for Your servant Isaac; and by this I will know that You have shown lovingkindness (faithfulness) to my master.”