Seller won’t sign contract.

We put in an offer on a house. Their realtor contacted our realtor and told us the seller verbally accepted our offer. I signed the purchase and sales agreement last Saturday and the seller keeps stalling on signing it. He kept saying he will sign it and it’s been 5 days and the seller hasn’t responded to his realtor since yesterday.

We don’t know why he keeps stalling and kept making excuses.

Is verbal agreement considered legally binding?

I’ve bought and sold houses in the past and never had to deal with this.