Abu Dawud
Jihad
Book Number: 008 / Hadith Number: 2524
Narated By AbuSa'id al-Khudri : A man emigrated to the Apostle of Allah (pbuh) from the Yemen. He asked (him): Have you anyone (of your relatives) in the Yemen? He replied: My parents. He asked: Did they permit you? He replied: No. He said: Go back to them and ask for their permission. If they permit you, then fight (in the path of Allah), otherwise be devoted to them.