Is saying, "Your hand is with us, O Lord," before doing something, with the intention of seeking blessings and remembering God, forbidden and considered audacious towards God?

The meaning of the supplication "The hand of Allah is above your hand" is correct; it is a request for help, blessings, protection, and care from Allah. Similar to it is the supplication of Imam Ahmad for Baqi ibn Makhlad: "May Allah elevate you to well-being, and wipe away [your ailment] with His healing right hand." Nevertheless, it is preferable to adhere to the reported supplications.