Genesis 17:25 And Ishmael his son was thirteen years old, when he was circumcised in the flesh of his foreskin. - Free Bible Online

Brief Summary: Abram is commanded by the Lord to walk perfectly, and God will make him a father of many nations, his name was changed to Abraham, the LORD makes a covenant to be a God to Abraham and to his seed for ever, God also promises to give Abraham the land of Canaan for an everlasting possession, circumcision becomes the token of God's everlasting covenant with Abraham, Sarai's name was changed to Sarah, Sarah will also bear Isaac and through Isaac the covenant will be established, Abraham and his entire household are circumcised.

Genesis Chapter 17

Genesis 17:5 - Neither shall thy name any more be called Abram, but thy name shall be Abraham; for a father of many nations have I made thee.

Outline
God Reveals His Name as El Shaddai  (Genesis 17:1-2)
God Confirms the Covenant (Genesis 17:2-4)
God Changes Abram's name to Abraham (Genesis 17:5)
Circumcision is Established (Genesis 17:9-14)
Sarai's Name is Changed to Sarah (Genesis 17:15-19)
God Promises Blessings to Ishmael (Genesis 17:20)
Abraham's Household is Circumcised (Genesis 17:21-23)
Abraham and Ishmael are Circumcised (Genesis 17:24-27)

Summary
1 God reneweth the covenant
5 Abram's name is changed in token of a greater blessing
10 Circumcision is instituted
15 Sarai her name is changed, and she blessed
16 Isaac is promised
23 Abraham and Ishmael are circumcised

Map of the Journeys of Abraham

The Journeys of Abram and Lot

Topics for Bible Study
Abram 99 Years Old
The Lord Appeared to Abram
El Shaddai
Abram Fell on His Face
Covenant Mentioned Again
Father of many Nations
His Name is Changed to Abraham
Exceedingly Fruitful
Nations Will Come From Thee
Kings will Come From Thee
Everlasting Covenant
I will Be a God to Your Seed
Your Seed Will Inherit the Land of Canaan
Everlasting Possession
Circumcision
The Flesh of his Foreskin
A Token of the Covenant
He that is Born in Thy House
He that is Bought With Money
Uncircumcised Man Child
Breaks the Covenant
Sarai's Name is Changed to Sarah
Mother of Nations
Abraham Laughed
Abraham Wanted Ishmael to Inherit
God Wanted Isaac
Ishmael Shall beget 12 Princes
Ishmael Shall be a Great Nation
Covenant with Isaac
Ishmael's Household Circumcised
Ishmael Circumcised at Age 13
Abraham was Circumcised at Age 99

Quick Reference Map

Map of the Jordan River (Click to Enlarge)

Historical Background
Abram is commanded by the Lord to walk perfectly, and God will make him a father of many nations, his name was changed to Abraham, the LORD makes a covenant to be a God to Abraham and to his seed for ever, God also promises to give Abraham the land of Canaan for an everlasting possession, circumcision becomes the token of God's everlasting covenant with Abraham, Sarai's name was changed to Sarah, Sarah will also bear Isaac and through Isaac the covenant will be established, Abraham and his entire household are circumcised.

Maps
Map of the Giants and Early Inhabitants of Ancient Israel
Map of the Canaanite Nations
Map of the World of Abraham
Map of the Journeys of Abraham

Clothing in the Time of Abraham

This is how a man or a patriarch would have dressed in ancient times about the time of Abraham which was around 1800 BC. From inside to out he wore an under garment which was bound by a girdle.

The Old Testament

Genesis Resources

Creation
Adam and Eve
The Flood
The Tower of Babel
Abraham the First Hebrew
Isaac, Son of Promise
Jacob and the 12 Tribes
Joseph and Egypt