en_tn/gen/18/19.md

that he may instruct

"that he will direct" or "so that he will command"

to keep the way of Yahweh ... Yahweh may bring ... he has said

Yahweh is speaking about himself as if he were another person. AT: "to obey what I, Yahweh, require ... I, Yahweh, may bring ... I have said" (See: rc://en/ta/man/translate/figs-123person)

to keep the way of Yahweh

"to obey the commands of Yahweh"

to do righteousness and justice

"by doing righteousness and justice." This tells how to keep the way of Yahweh.

so that Yahweh may bring upon Abraham what he has said to him

"so that Yahweh may bless Abraham just as he said he would." This refers to the covenant promise to bless Abraham and make him a great nation.