According to tradition (see Rashi commentary to Exodus ch.13), the majority of the Israelites had become idolaters in Egypt (Ezekiel ch.20) and were not deemed worthy of joining the Exodus - or didn't want to. Those who did leave Egypt were 20% of the Israelite populace (Rashi, Exodus 13).
The bones of Joseph (Genesis 50, Exodus 13).
It was when the Israelites left Egypt and journeyed to Canaan (Israel) as narrated in the Hebrew Bible.
The Israelites did not escape. They left Egypt in an orderly fashion, with their livestock, after receiving Pharaoh's permission to do so (Exodus ch.12).
That it is not known. A tradition states that there were Israelites who, due to assimilation, were uninterested in leaving Egypt and died off before the Exodus (Rashi commentary, Exodus 13:18), while others may have survived and stayed behind (Rabbi Miller). See also:How many Israelites left Egypt?Evidence of the Exodus
God told them to (Exodus 3), after having promised to give them that land (Genesis 28).
The Torah tells us that the Israelites left Egypt and arrived in the land of Israel after 40 years in the Sinai desert.
It says they left Egypt in haste.
The Exodus. (The word "flight" is not accurate, because the Israelites left Egypt in an orderly fashion under the leadership of Moses, after having been given leave to depart by Pharaoh).
When Israel left Egypt, they were a people without a purpose or union, but the act of leaving Egypt, combined with receiving the commandments, formed the Israelites into a people with a unified identity and mission. In effect, the exodus forged the Israelite identity and it was as if the people were redefined and recreated for their new mission.
The Ten Plagues, sent by God (Exodus ch.7-12), softened up the Egyptians; and the last Plague left them reeling.
The Israelite s left Egypt for Canaan.
They left the city of Ramses (Exodus 12).