Responses
He also probably knows how well Illiya would be in a country that actually acknowledges and respects him. Not only was he revered because he was an omega, considered a messenger from their god, he also was the backbone of the country when it fell apart from Zane (spelling) and kept people together and was quite literally a mother to his people. So yeah I bet Illiyas dad was like “thanks for visiting me but please go home you are better off there than this cold place”
Let's assume that the dads (both Khalid and ilya's) doesn't know how to act around their children, but they are not entirely bad. That's how they were raised after all, so saying to Ilya that he should leave immediately means he knows that his eldest means no good to Ilya, god I hate those kind of characters where you can see that they are not entirely bad.