Anyway, back to topic....
It's mentioned in the LOTR Appendices, though : he was the one who opposed to the marriage of Gilraen and Arathorn, as he felt Arathorn wouldn't live long - but his wife Ivorwin convinced him.
Obviously it was lucky for Aragorn, and the whole of Middle Earth, that Ivorwin did convince Dirhael to allow Gilraen to marry Arathorn. It begs the question, had this marriage not taken place, would the son of Arathorn and whoever he did marry have the strength of character that Aragorn had, or was Aragorn "special"? Was Aragorn the product of the very best the Dunedain had to offer?
The reason I ask this is because Dirhael himself was a descendant of Aranarth, the first Chieftain.