לַשַּׁ֣חַת קָ֭רָאתִי אָ֣בִי אָ֑תָּה אִמִּ֥י וַ֝אֲחֹתִ֗י לָֽרִמָּֽה׃
If I have said to corruption: ‘Thou art my father’, To the worm: ‘Thou art my mother, and my sister’;
Rashi on Job
To the pit I have called, ‘You are my father,’ to lodge there many days as though it was my father, since this is my hope.
Malbim on Job
The Hebrew text has אמי, meaning 'my mother'. But Malbim reads this as אחי, meaning 'my brother', which makes more sense.