"Hmmmm, yes." Odin pretended to think it over, wanting to give the boy the impression that he needed to weigh his options. Whether Hermod saw it that way or not, this was a big deal, almost a passage to manhood. For he would no longer be just the son of Odin, but a god in his own right, with his own purpose.
Ignoring what he had to say regarding Baldr and Hodr (for what brothers didn't keep secrets?), Odin nodded slowly.
"I guess I'm AM going to need someone to look after him," at this Odin gestured his head toward Sleipner. "That's a lot of responsibility, running about for me and taking care of my prize horse." The Valfather was pleased that Hermod had immediately jumped up to the challenge. It showed initiative and a desire to please. Should Odin have forced this on his son, he might never have achieved the enthusiasm necessary for what could prove in time to be a full time job. There were other pantheons to consider as well, as the Northern people grew in number and explored the world.
"Alright, tell you what. You show me you can handle taking care of Sleipner, training him, grooming and feeding him, and the like, as well as handling delivering any messages I might need here in Asgard, and then we'll see. You do well, and I will speak to Heimdall about letting you beyond the borders."
Odin had no doubt that Hermod would prove his worth, and that before the year was out the youth would be traveling to Midgard and beyond on his own. He clapped his hand on his son's shoulder with a grin. "Of course, that would mean I'd have to get you a sword, I suppose. Can't have you trapsing about Midgard on your own without a weapon, can I? And perhaps, someday, you will be allowed to ride Sleipnir if your duties require it."