Augustine of Hippo — as excerpted in the Catena Aurea on John 2:18-22

“(b. lxxxiii. Quæst. 2. 5. f.) The process of human conception is said to be this. The first six days produce a substance like milk, which in the following nine is converted into blood; in twelve more is consolidated, in eighteen more is formed into a perfect set of limbs, the growth and enlargement of which fills up the rest of the time till the birth. For six, and nine, and twelve, and eighteen, added together are forty-five, and with the addition of one (which1 stands for the summing up, all these numbers being collected into one) forty-six. This multiplied by the number six, which stands at the head of this calculation2, makes two hundred and seventy-six, i. e. nine months and six days. It is no unmeaning information then that the temple was forty and six years building; for the temple prefigured His Body, and as many years as the temple was in building, so many days was the Lord’s Body in forming.”