the Patriarch Abraham - See Chapter VI, Mishnah 8.

derived from - taught by Abraham orally and passed down through the generations.

Until the oral teaching reached the generation of Rabbi Akiba.  Rabbi Akiba is the final redactor of the Book of Formation.  He delivered this definitive version to his students (most likely only in oral form).

"Akiba" is an ordinary English spelling.  Hebrew speakers say "Akiva."

derived from - Rabbi Akiba, as the final redactor of the Book of Formation, arrived at a definitive version that incorporated accurate teachings from the Patriarch Abraham.  Teachings in oral form were not uncommon.  Ancients were well-practiced in memorization.

A pitfall arises in listening and hearing homonyms, though.

a.m. - anno mundi; Latin for "in the year of the world" referring to the traditional Hebrew expression: "from the creation of the world," i.e, the year since creation of the world.

ce - Common Era; the counting of years as used in the western world and elsewhere.  The expression for the abbreviation "a.d." refers to a counting since Jesus's birth.  Jews have been reluctant to use this previously Christian reference even though it has become a secular convention.