It is permissible to offer the Funeral Prayer on recently buried Muslims if there is someone who did not formerly offer it on the same person even if they did not know them. This is proven by a narration that is related in the Two Sahih (authentic) Books of Hadith (Al-Bukhari and Muslim) on the authority of
Ibn `Abbas (may Allah be pleased with them both) who said: (Part No. 8; Page No. 392)
The Messenger of Allah (peace be upon him) went to a grave that had been newly prepared and prayed over it, and those who were behind him also prayed and he recited four takbirs.
Visiting graves is a Sunnah (a commendable act) for relatives and others to receive admonition, remember the Hereafter, and make Du`a' for the dead.
Ibn Majah narrated
on the authority of
Buraydah (may Allah be pleased with him), who said:
Allah's Messenger (peace be upon him) used to teach them (the Companions) whenever they came to visit the graveyard to say: "Al-Salamu `alaykum ahl-al-Diyyari min-al-Mu'minina w-al-Muslimina, wa inna in sha'a Allahu bikum lahiqun. Nas'al-ul-Laha lana wa-lakum-ul- `Afiyah (Peace be upon you, O inmates of the abodes of the believers and the Muslims, and Allah willing we shall join you. We pray to Allah for well-being for ourselves and for you).''
May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.