אַ֭חַי בָּגְד֣וּ כְמוֹ־נָ֑חַל כַּאֲפִ֖יק נְחָלִ֣ים יַעֲבֹֽרוּ׃
מײַנע ברידער האָבן געפֿעלשט װי אַ טײַך, װי דער שטראָם פֿון טײַכן װאָס גײען אַװעק,
Sforno
בא גד, this one came coincidentally, for I had not planned to bring him into the world, seeing that I had stopped giving birth. The reason why the word is spelled as a single word with the letter א missing, is to indicate that the conception and pregnancy was not planned but occurred gratuitously. Her pregnancy had somehow become terminated after it had begun. We find a similar construction of the word בגד in Job 6,15: אחי בגדו כמו נחל, “my comrades are fickle like a wadi.”