Can you pair ID and Class selectors together when creating a Descendent Selector?

Since you can pair an ID and class selector with a type/element selector in order to create a descendent selector could you do the same with ID and class? for example, say your HTML looks like this:

<header class="main"> <p id="first">This is my first paragraph</p> </header>

could you then create a decedent selector pairing the class of the header with the ID of the p element in order to apply a CSS rule to that specific p tag? like this

.main #primary {padding: 10px;}

or since any rules applied to ID's overrule any rules applied to classes would this end up not working out? or could you do the inverse if your HTML looked like this:

<header id="main"> <p class="primary>This is my primary paragraph</p> </header>

#main .primary {margin: auto;}

Just curious any insight is appreciated :-)