The different Hebrew and Greek terms that are translated as “(olive) oil” and “(animal) fat” in English are translated in Kwere with only one term: mavuta. (Pioneer Bible Translators, project-specific translation notes in Paratext)
Translation commentary on 2 Kings 4:4
Go in: This verb is the opposite of “Go outside” in verse 3 and means the widow is to go back into her own house. In the view of the New American Bible translators, Elisha was giving instructions to the widow while at her house. They therefore find it more natural to translate this verb “come back.” But there is nothing in the context that indicates that Elisha went to the woman’s house. The contextual clues point rather to the fact that she must have gone to Elisha. For this reason it will be better to use a verb meaning “go back home.”
Shut the door upon yourself and your sons: This expression is clearly intended to emphasize the privacy of what takes place next. The door of the house is to be closed so that only the woman and her sons are inside. In some languages it may be necessary to say “be sure that no one but you and your sons are in the house, then close the door.”
Revised Standard Version refers to the sons as “children” in verse 1, but the Hebrew word there for “children” nearly always refers to male children. The fact that they were both male is new information at this point in the Hebrew text. However, certain English versions take the word sons in this context as being more generic and continue to translate “children” here (New Jewish Publication Society’s Tanakh, New American Bible).
Pour into all these vessels: Pour will require an object in many languages. The meaning is obviously to pour some of the oil mentioned at the end of verse 2 into the containers. Nouvelle version Segond révisée adds the words “the oil” in parentheses, but this implicit information may be made explicit without the use of parentheses (so Good News Translation, Contemporary English Version, New International Version, Nouvelle Bible Segond).
When one is full, set it aside: Each time one of the containers was full, the widow was instructed to remove it from the area where the pouring was taking place. Some may say “each time you fill one of the containers, put it in another place.”
Quoted with permission from Omanson, Roger L. and Ellington, John E. A Handbook on 1-2 Kings, Volume 2. (UBS Helps for Translators). New York: UBS, 2008. For this and other handbooks for translators see here .