Where it is written can be made explicit. You can also translate this in an active form. Alternate translation: "as someone has written in the Scriptures" (See: [[rc://en/ta/man/translate/figs-explicit]] and [[rc://en/ta/man/translate/figs-activepassive]])
Here "of him whom he trusted" refers to God. Alternate translation: "Abraham was in the presence of God whom he trusted, who gives life to those who have died" (See: [[rc://en/ta/man/translate/figs-explicit]])