Question: Isaac said, “Doesn't Genesis 11:26 say that Terah was 70 years old when he had Abram?” In the Patriarch's Timeline Terah was 130 when Abram is born.
Answer: Well done for checking the Scriptures Isaac, there’s much profit in doing so.
“After Terah had lived 70 years, he became the father of Abram, Nahor and Haran” (Gen 11:26).
Abram’s name is mentioned first in the Genesis list of Terah’s sons because he was the most influential in the rest of the story, and first also on account of his spiritual pre-eminence - he is in the Messianic line and so the spiritual birthright belongs to him. But we know Abram couldn’t be the firstborn.
The criteria for having your name first in a family list of brothers is not necessarily down to age – Another example is Noah’s sons: Gen 5:32 - “After Noah was 500 years old, he became the father of Shem, Ham and Japheth," but Gen 10:21 tells us that Shem’s older brother was Japheth. Shem was also in the line to Christ, hence his name appears first.
Terah, had three sons, Abram, Nahor, and Haran. Abram’s name is first for reasons other than date of birth.
Stephen, in Acts 7:4, tells us that Abraham left the city of Haran (no link to his brother Haran) after his father Terah died, and Terah died at the age of 205 (Gen 11:32). Genesis 12:4 informs us that Abram was 75 when he left the city of Haran, making Terah 130 when Abram was born.
Haran seems to be the firstborn, partly because he died first and partly because one of his daughters married his brother Nahor. So Haran was born when his father was 70 years old and we know that Abram was born when his father was 130, which would make Haran 60 years old when Abram was born.