'Baby' in the Bible

But the Lord asked Abraham, “Why did Sarah laugh, saying, ‘Can I really have a baby when I’m old?’

She said, “Here, take my maid Bilhah and go in to her; and [when the baby comes] she shall deliver it [while sitting] on my knees, so that by her I may also have children [to count as my own].”

And when she was in labor, one [baby] put out his hand, and the midwife took his hand and tied a scarlet thread on it, saying, “This one was born first.”