I know well enough what it is, provided that nobody asks me; but if I am asked what it is and try to explain, I am baffled.
AUGUSTINE, Confessions, Book XI
When it came to the beginning of creation, Augustine was not the only person who struggled with the meaning of time. Rabbinic wisdom teaches that there are some aspects to creation that are hidden; we cannot presume to know the mind of God. “Why does the Torah begin with the letter בּ (beth = “b”)? Just as the letter בּ (beth) is closed at the sides but is open in front, so you are not permitted to investigate what is above and what is below, what is before and what is behind.” The Judean sage Jesus ben Sirach (is 200–180 B.C.E.) offers this practical advice to those who speculate about the “hidden matters” alluded to in the
Neither seek what is too difficult for you,
nor investigate what is beyond your power.
Reflect upon what you have been commanded,
for what is hidden is not your concern.
Do not meddle in matters that are beyond you,
for more than you can understand has been shown you.
Such an answer may have been intended to keep the masses away from Gnostic speculations. Rabbinic wisdom teaches that there can be no definitive answer to such a question since time and space did not yet exist, except as a mere potentiality.
Gen. Rabbah 1:10.
 This passage is cited in the Talmud in BT Hagigah 13a and in T.J. Hagigah 77C, and in Gen. Rabbah 8:2. “R. Leazar said in Bar Sirach’s name: ‘About what is too great for thee inquire not; what is too hard for thee investigate not; about what is too wonderful for thee know not; of what is hidden from thee ask not; study what was permitted thee; thou hast no business with hidden things’.” Sirach’s responses is reminiscent of God’s response to Job 38:1-7:
Then the Lord answered Job out of the whirlwind:
“Who is this that darkens counsel by words without knowledge?
Gird up your loins like a man,
I will question you, and you shall declare to me.
Where were you when I laid the foundation of the earth?
Tell me, if you have understanding.
Who determined its measurements—surely you know!
Or who stretched the line upon it?
On what were its bases sunk,
or who laid its cornerstone
when the morning stars sang together
and all the heavenly beings shouted for joy?