Luke 1:57

But the time was fulfilled for Elizabeth that she should bring forth, and she gave birth to a son.

Genesis 21:2-3

And Sarah conceived, and bore Abraham a son in his old age, at the appointed time of which God had spoken to him.

Numbers 23:19

God is not a man, that he should lie; neither a son of man, that he should repent. Shall he say and not do? and shall he speak and not make it good?

Luke 1:13

But the angel said to him, Fear not, Zacharias, because thy supplication has been heard, and thy wife Elizabeth shall bear thee a son, and thou shalt call his name John.

Luke 2:6-7

And it came to pass, while they were there, the days of her giving birth to her child were fulfilled,

Treasury of Scripture Knowledge

Summary

Now Elisabeth's full time came that she should be delivered; and she brought forth a son.

Bible References

General references

Luke 1:13
But the angel said to him, Fear not, Zacharias, because thy supplication has been heard, and thy wife Elizabeth shall bear thee a son, and thou shalt call his name John.
Luke 2:6
And it came to pass, while they were there, the days of her giving birth to her child were fulfilled,
Genesis 21:2
And Sarah conceived, and bore Abraham a son in his old age, at the appointed time of which God had spoken to him.
Numbers 23:19
God is not a man, that he should lie; neither a son of man, that he should repent. Shall he say and not do? and shall he speak and not make it good?