Matthew Poole and continuators on Psalms 123:2

2 Behold, as the eyes of servants look unto the hand of their masters , and as the eyes of a maiden unto the hand of her mistress: so our eyes wait upon the LORD our God, until that he have mercy upon us .

Either, 1. for supply of their wants, which comes from their masters hand: or, 2. for pity, the hand being the instrument whereby masters commonly correct their servants, and looking to the hand may express the posture of one supplicating for mercy: or rather, 3. for help and defence against their oppressors. For servants were unable to defend themselves, and were not allowed to wear defensive weapons, but expected and had protection from their masters in case of injury. For this phrase of having ones eyes towards another both in this and other sacred Books, constantly notes expectation and desire of help from them, as Psal. 25. 15. & 69. 4. Isa. 17. 7. Ezek. 23. 27. and oft elsewhere. And the phrase of Gods having mercy upon another, doth most commonly signifie that act or effect of his mercy in helping and delivering him.

Until he graciously help and save us.