The language of the page is more important; so in the example of .de, you want your content to be in German; then linking to such a page in German from a .de site should help slightly more than from a .com, especially if the .com is in English; in summary:
1/ best is link from .de in German to your .de in German;
2/ second best is link from .de in German to your .com in German.
As always "it depends"; but if you target #1, it should certainly help; for page 1 only, you probably don't need it.