Can we include a religious meal blessing at a wedding we've planned as secular?

My future father-in-law offered to give thanks before dinner. We said yes, thinking he meant a short welcome. His draft begins by asking everyone to bow their heads and ends with words about bringing our marriage into his faith.

We aren't having a religious ceremony. My partner values his dad's beliefs and says guests who don't share them can stay quiet. I don't want our first meal as a married couple introduced in terms that describe a commitment we haven't made.

His dad sent the text because he wanted us to approve it, so this is still a conversation we can have. I would be happy to hear him express gratitude in his own voice. I'm struggling with the part where he tells the whole room what our marriage means.

How do we explain that distinction without asking him to pretend his faith isn't important to him?