It is because we are forgetful and Guru Maharaj Ji (great king) knows everything. The things that are meant to be emphasized are repeated by Maharaj Ji. It’s up to them, they are the Guru (Enlightener). The one who is a Guru teaches and the one who is a Sikh accepts. May the Sikh never say to Guru Sahib Ji, “Why are you teaching me this?” Now look, some Sikhs say and fight over why Maharaj didn’t do this or that. Go and ask them, “Would you change Mool Mantar (root mantra)?” Nobody can change Mool Mantar. But if someone stood up and said, “Guru Ji should have put the word Meharvaan (merciful) in the Mool Mantar” and said, “Why isn’t it there? Put it in the Mool Mantar!” Nobody would do this. Whatever Guru Ji said, we are to accept it. There is a lot in what Guru Sahib Ji tells us and if it is repeated, so what?

You can watch Bhai Jagraj Singh explain this in the video below: