Tamar Braxton's estranged husband, Vincent Herbert, is stunned by his mother-in-law's strong insinuation he's an abusive man capable of killing her daughter ... and he totally denies it.
A source close to Vincent tells TMZ ... he has no idea why Evelyn Braxton told us she's fearful his impending divorce from Tamar could get deadly because he's no abuser -- he loves Tamar and would never hurt her.
We're told Vincent's upset over Evelyn's comments because he feels this type of story could negatively affect their 4-year-old son when he's older. Our source says Vince doesn't want beef with Evelyn ... he says he's going to pray for her.
Our source says Herbert still plans to fight to win Tamar back and reconcile their marriage despite what her family wants ... and be a good dad in the process.