Abraham left Ur at 13 years old
Based on Abraham’s timeline he would have been born in 1967 BC and exited Ur in 1954 BC, giving him an age of about 13 years of age. This figure makes sense, seeing 13 is often considered an age of accountability. Abraham circumcised his son at the age of 13 in Genesis 17. The Bible informs us that when Jesus was 12 years old, he went to the temple as it was customary in those times and was accidentally left there. The Jews in modern times also have a bar mitzvah at the age of 13. When Jews reach the age of accountability, frequently 13 years old, and choose to follow God, they have a bar mitzvah.
The same idea is often followed in Christian churches. Often, when children are raised in a church, they choose to follow God and be baptized around 13 years of age. I was raised in the church, and by the time I reached 12 years of age, I chose to follow Jesus. I chose to follow Jesus even though I legally had to go where my parents went and live where my parents lived. Even though I was still dependent on them to meet my needs, I still chose with all of my ability to follow God, giving Him credit for all.
Abraham, being 13 years of age, would not want to live on his own. When Abraham’s father left Canaan, he would have wanted to take Abraham with him. The act of Abraham choosing to go with his father when he left the sinful city of Ur pleased God.