Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him) said: A man from Yemen emigrated to the Prophet (peace and blessings be upon him). The Prophet (peace and blessings be upon him) said to him: "You have abandoned polytheism, but jihad remains. Are your parents in Yemen?" He replied: "Yes." The Prophet (peace and blessings be upon him) asked: "Did they give you permission?" He replied: "No." So the Prophet (peace and blessings be upon him) said: "Go back to your parents and ask their permission. If they give it, well and good; otherwise, keep treating them well."
Ahmad recorded it, and its chain is hasan (good).