That is why many of his students throughout the last 500 years have lost sleep over the following conundrum. He rules in the laws of Rosh Chodesh that we don't make a bracha on Hallel because Hallel on Rosh Chodesh is only a minhag and we don't make brachas on minhagim.
Great - so what's the conun?
Glad you asked!
In hilchos chanuka he rules that when lighting chanuka candles in shul a bracha IS made despite the fact that it's a minhag.
Uh oh!
So do you make a bracha on a minhag or not?
What does this have to do with anything? Well it's Torah and we learn Torah together. Plus, as I write my sister in law is over at my house and her name is Brachi so it's the time to talk about brachos.
If you want to learn more, open יביע אומר ח"ז סימן נז and make sure to guard your breath otherwise this teshuva will TAKE IT AWAY.
Wow!
The man is a TITAN.