Komentarz do Diwrej ha-jamim I 19:11

into the hands of Abshai To Abishai, who is called Abshai throughout the entire Book of Chronicles, both in the written text and in the reading, except for these two cases, which are exceptions to the rule according to the Masorah. The reason that he is called Abshai in this entire Book is because it was written in David’s honor, and it is not honor to call his nephew Abishai, meaning: “I, too, am as esteemed as David because my [grand]father was Jesse [Yishai]” Therefore, in this entire Book, he is called Abshai, and in the entire Book of Samuel he is called Abishai, except once, where he is called Abshai: (II Sam. 10:10): “And the rest of the people he gave over to Abshai his brother.” This is according to the Masorah, because Jesse was the father of his mother, Zeruiah, who was his mother.