Ephraim Speiser argued that in spite of its surface unity, the Joseph story, on closer scrutiny, yields two parallel strands similar in general outline, yet markedly different in detail. The Jahwist’s version employed the Tetragrammaton and the name “Israel.” In that version, "Judah" persuaded his brothers not to kill Joseph but sell him instead to "Ishmaelites", who disposed of him in Egypt to an "unnamed" official. Joseph's new master "promoted" him to the position of chief retainer. When the brothers were "on their way" home from their first mission to Egypt with grain, they opened their "bags" at a night stop and were shocked to find the payment for their purchases. "Judah" prevailed on his father to let Benjamin accompany them on a second journey to Egypt. Judah finally convinced Joseph that the brothers had really reformed. "Joseph" invited Israel to settle with his family in "Goshen". The Elohist’s parallel account, in contrast, consistently used the names “Elohim” and “Jacob.” Reuben — not Judah — saved Joseph from his brothers; Joseph was left in an empty cistern, where he was picked up, unbeknown to the brothers, by Midianites; they — not the Ishmaelites — sold Joseph as a slave to an Egyptian named Potiphar. In that lowly position, Joseph served — not supervised — the other prisoners. The brothers opened their sacks — not bags — at home in Canaan — not at an encampment along the way. Reuben — not Judah — gave Jacob — not Israel — his personal guarantee of Benjamin's safe return. Pharaoh — not Joseph — invited Jacob and his family to settle in Egypt — not just Goshen. Speiser concluded that the Joseph story can thus be traced back to two once separate, though now intertwined, accounts.