The following information lets the Bible explain what leaving Egypt means.

Numbers 33.3 And they <departed> from Rameses in the first month, on the fifteenth day of the first
month; on the morrow after the Passover the children of Israel went out with an high hand in the sight
of all the Egyptians.

The word <departed> is Strong’s #05265.  The parsing is #8799.  The stem is Qal.  The
mood is imperfect.  The word can mean to <set out>.  The Israelites set out on their
journey on the 15th day of Nisan at daybreak (in the sight of all the Egyptians), when they
left their homes, headed out of Egypt.

05265 naca` {naw-sah'}

a primitive root; TWOT - 1380; v

AV - journey 41, departed 30, remove 28, forward 18, went 8, go away 3,
brought 3, set forth 2, go forth 3, get 1, set aside 1, misc. 8; 146

1) to pull out, pull up, set out, journey, remove, set forward, depart
1a) (Qal)
1a1) to pull out or up
1a2) to set out, depart
1a3) to journey, march
1a4) to set forth (of wind)
08799 Stem  - Qal
Mood  - Imperfect
Count - 19885

Ex 12:41 And it came to pass at the end of the four hundred and thirty years, even the selfsame day it
came to pass, that all the hosts of the LORD went out from the land of Egypt.

The words <went out> also mean to depart.  In most cases the term used is, “brought
out.”  This is a figure of speech, which means to accomplish the task of making it possible
so they could depart, if the Bible is referring to the beginning of their journey.  The
reason it is important to understand the difference is that it took more than one day to
leave Egypt.  They left Egypt on the 7th day of Unleavened Bread when they crossed the
Red Sea.

If the term "brought you out of Egypt" refers to the beginning of their journey, the
implication is of the power of God, by means of the 10 plagues.  Deuteronomy 16.1 would
than focus on the final plague, which broke the will of the Pharaoh and made it possible to
bring Israel out of Egypt.  The Hebrew word used for “brought thee forth” is Hiphil
Perfect which means “caused to bring you forth” indicating a figure of speech.  Strong’s
Concordance indicates that one may use this word figuratively.  When we put
Deuteronomy 16:1 with all the other scriptures on the subject, the Israelites came out of
Egypt by day (literally) and they were brought out of Egypt by night (figuratively).  Of
course, this verse could also refer to the night crossing of the Red Sea – if it requires a
literal interpretation.  Figuratively God brought them out of Egypt at midnight of the
15th.  However, God brought them out of Egypt by night literally, when they crossed the
Red Sea.  However, the Hebrew Hiphil Perfect verb for the word brought, suggests a
figure of speech reference to the night of the 15th Nisan.

Exodus 13:3 And Moses said unto the people, Remember this day, in which ye came out from Egypt,
out of the house of bondage; for
by strength of hand the LORD brought you out from this [place]:
there shall no leavened bread be eaten.
4 This
day came ye out in the month Abib.

The Bible says at least 8 times that Israel left Egypt by day.  The Bible says one time that
God brought them out by night.  Now, we have to reconcile these verses in order to come
to truth – and the bible does not contradict itself.

In reality, God was bringing the Israelites out of Egypt from the time of the first plague,
which may have been as much as a year earlier.  The Israelites were still in Egypt when
they settled down at Succoth.  This shows that a <figure> is being used when the bible
says <they left> or <were brought out> of Egypt, at anytime before the Red Sea
crossing.  However, this one verse of Deuteronomy 16:1 is definitely referring to what
God did, not what the Israelites did.  God broke the back of Egypt during the night of the
15th.  The Israelites began their journey at daybreak when they left their homes packed
for their exodus out of the land of Egypt.  God literally brought Israel out of Egypt on the
night they walked through the Red Sea on dry land.  At daybreak, God released the
waters upon the Egyptians and they drowned in the sea.