Adam Clarke on Isaiah 33:2

Be thou their arm every morning "Be thou our strength every morning" - For זרעם zeroam, their arm, the Syriac, Chaldee, and Vulgate read זרענו zeroenu, our arm, in the first person of the pronoun, not the third: the edition of Felix Pratensis has זרעתינו zerootheynu in the margin.

The prophet is here praying against the enemies of God's people; and yet this part of the prayer seems to be in their behalf: but from the above authorities it appears that Our arm is the true reading, though I do not find it confirmed by any of Kennicott's, De Rossi's, or my own MSS. My old MS. Bible has, - Be thou oure arm in erly.