JST Genesis 16:1–6 depicts Abraham as a polygamist, with Sarai as his wife and Hagar as his concubine.
Joseph Smith, Old Testament Revision 1 [Genesis 16], 36–37, The Joseph Smith Papers website, accessed June 10, 2022
Now Sarai Abrams wife bear him no children and she had a handmaid an Egyptian whose name was Hagar and Sarai said unto Abram b[e]hold now the Lord hath restrained me from bearing I pray thee go in unto my maid it may be that I will <may> obtain children by her and Abram hearkened unto the voice of Sarai and Sarai abram’s wife wife took Hagar her maid the Egyptian after Abram had dwellt ten years in the land of Canaan and gave her to her husband Abram to be his wife and he went in unto Hagar and she conceived and when she saw that she had conceived her mistress was dispised in her eyes and Sarai said unto Abram my rong is upon thee I have given my maid into thy bosom and when she saw that she had conceived I was dispised in her eyes the Lord judge between me and thee but Abram said unto Sarai behold thy maid is in thy hand do to her as it pleaseth thee and when Sarai dealt hardly with her she fled from her face