Adam Clarke on Job 19:17

Though I entreated for the children's sake of mine own body - This may imply no more than adjuring her by the tenderest ties, by their affectionate intercourse, and consequently by the children which had been the seals of their mutual affection, though these children were no more. But the mention of his children in this place may intimate that he had still some remaining; that there might have been young ones, who, not being of a proper age to attend the festival of their elder brothers and sisters, escaped that sad catastrophe. The Septuagint have, Προσεκαλουμην δε κολακευων υἰους παλλακιδων μου, "I affectionately entreated the children of my concubines." But there is no ground in the Hebrew text for such a strange exceptionable rendering. Coverdale has, I am fayne to speake fayre to the children of myne own body.