SimchaMinute by Rabbi Avigdor Miller
When people raise up a big family... but they forget the purpose, it’s a major tragedy. All that work — getting married is a big job and raising up a family is a big job... but you should do it l’shem shamayim (for the sake of Heaven)...
You have lost most of the benefit if you didn’t have the intention of l’shem shamayim. — Building the Bais Yisroel (#764)