The first-born Vashni, and Abiah - There is a great mistake in this verse: in 1 Samuel 8:2; we read, Now the name of his (Samuel's) first-born was Joel; and the name of his second Abiah. The word יואל Joel is lost out of the text in this place, and ושני vesheni, which signifies the second, and which refers to Abiah, is made here into a proper name. The Septuagint, Vulgate, and Chaldee, copy this blunder; but the Syriac and Arabic read as in 1 Samuel 8:2. The MSS. have all copied the corrupted Hebrew in this place. Jarchi labors to restore the true reading, and yet preserve the integrity of the text, by paraphrasing thus: "And the second, (ושני vesheni ), in respect of the first, he was Abiah; and the second, in respect of Abiah, he was Joel."
These, Joel and Abiah, were the two sons of Samuel, who administered justice so badly that the people, being oppressed, began to murmur, and demanded a king. See 1 Samuel 8:1, etc.
Vashni - The true name of Samuel‘s first-born, which was “Joel” (see the margin and references), has here dropped out; and the word properly meaning “and his second (son)” has been taken as the name of the first.