Why does my dog bark at my husband?

Toby is a loving dog and is nice to everyone, however he's started to bark at my husband (Only had Toby for about 5 weeks now).

It's only when my husband is sat down watching TV and Toby walks in and lays on the carpet, but then he will stand up and bark at him.
It doesn't seem like a nasty bark, perhaps he just wants to play (Something my husband doesn't do).

There was once a moment though where we were both sat down in the living room and all of a sudden Toby started to Growl at him. He wasn't snarling, just a growl.
My husband reacted by just staring at him - Something I've heard conflicting things about, some people say to do it to show who is boss, others say don't do it, it's dangerous. In the end Toby backed down and stopped, but I felt very uncomfortable about it all and we weren't sure why he started doing that and we weren't sure if it was the correct approach.
I don't stroke Toby or give him positive attention when he barks at hubby.

Although once I wanted to try this Alpha stuff, I decided not to but it seems I've become that person by accident. He does a submissive roll onto his back and when I stroke him he is submissive and head down (Until I stop and then he gets all excited and jumpy).

I'm not in the room when Toby barks at him, it's not a constant bark, it's just a quick little bark and hubby tells him to Shh in a firm tone.

Why is Toby doing this? Is it for play? Is it some kind of ranking?

The growling happened last week, and this barking started a few days later, again, it doesn't seem like a nasty bark.

We don't want to mess up.

Is Toby a rescue?? If so do you know anything of his history??

It sounds like he may be insecure with your hubby, a little scared mibby
Honestly I would ditch all thougths of alpha stuff and please please dont stair him down - that is a great way to get bitten - if you watch dogs just before a fight you will often see hard stairing
It does nothing to prove alpha - a dog is a dog, a human a human

How about you try and make him comfy around hubby?
Get hubby to get some nice treats and teach him fun behaviours like sit and down being really rewarding - even hand feed his dinner like this for a little while so he associates your hubby with really nice thing
and at times where in the past he has told you he is uncomfy try making it a fun game for him - hubby chucks a handfull of kibble before he stands up - and some more once he has stood up
he drops some chicken when he walks in the room

Over time Toby should start being less stressed by these things

Barking and growling are communications - him saying he isnt happy with something - that is a good thing
If he is punished for making the noise he will still be unhappy - just quiet - and then if pushed further he could bite with no warning - because he has learnt that warnings dont work

Thank you Ben

I have just been told the same by someone else, and I don't want to do this Alpha malarkey anyway
My husband doesn't interact with Toby much to be honest, he's not one to fuss over a dog, he will stroke him from time to time but I think you're onto something about their relationship.

I've sent him out to walk Toby (Normally I walk him or I come with my husband) on his own.
I am the one who treats and feeds Toby and doing bits of training.

I have read more and found that staring is a threatening thing to do so I will explain to my husband.

He is a rescue dog, we've had him for 5 weeks so I guess he's still settling down here.
He was found and was the width of his spine, I'm still trying to fatten him up and get him used to food.

We suspect he was abused too. The other day I firmly said 'No' and moved my foot to move him out of the way (not to kick, just to move him along - hands full) and he screeched and yelped! I hadn't touched him! Poor thing :'(

Thank you, I will get hubby to do the treats from now on and feeding times Thanks