In early times custom required the bridegroom, before the ratification of a marriage engagement, to pay a sum of money or its equivalent in other property, according to his circumstances, to the father of his wife. This was regarded as a safeguard to the marriage relation. Fathers did not think it safe to trust the happiness of their daughters to men who had not made provision for the support of a family. If they had not sufficient thrift and energy to manage business and acquire cattle or lands, it was feared that their life would prove worthless. But provision was made to test those who had nothing to pay for a wife. They were permitted to labor for the father whose daughter they loved, the length of time being regulated by the value of the dowry required. When the suitor was faithful in his services, and proved in other respects worthy, he obtained the daughter as his wife; and generally the dowry which the father had received was given her at her marriage. In the case of both Rache…
The EGW passage elaborates on the custom of the bridegroom paying a dowry or working for the bride's father, which is the context for Jacob's service for Rachel in Genesis 29:18. The EGW passage provides cultural context and explanation, making it a thematic parallel.
"Seven years of faithful service Jacob gave for Rachel, and the years that he served “seemed unto him but a few days, for the love he had to her.” But the selfish and grasping Laban, desiring to retain so valuable a helper, practiced a cruel deception in substituting Leah for Rachel. The fact that Leah herself was a party to the cheat, caused Jacob to feel that he could not love her. His indignant rebuke to Laban was met with the offer of Rachel for another seven years’ service. But the father insisted that Leah should not be discarded, since this would bring disgrace upon the family. Jacob was thus placed in a most painful and trying position; he finally decided to retain Leah and marry Rachel. Rachel was ever the one best loved; but his preference for her excited envy and jealousy, and his life was embittered by the rivalry between the sister-wives. PP 189.2"
The EGW passage directly quotes Genesis 29:20, making it an explicit allusion.