This is a hadeeth which those who support tawassul through the prophet use.
From Anas ibn Maalik who said: “When Fatimah bint Assad ibn Haashim, the mother of ‘Alee, died, he called Usaamah ibn Zayd, Aboo Ayyoob al-Ansaaree, Umar ibn al-Khattaab, and a young black boy to dig the grave… then when they had finished Allah’s Messenger entered and lay her down there and said: “It is Allaah who gives life and gives death, and He is the Ever-Living who never dies, forgive my mother Fatimah bint Assad, and grant her proof, and grant her a spacious place by the right of Your Prophet, and the Prophets who came before me, for indeed You are the Most-Merciful of those who show mercy…” Reported By At-Tabaraanee
Al-Haithumee said in Majma’ uz-Zawaaid (9/257): “At-Tabaraanee reports it in al-Kabeer and al-Awsat and it contains Rawh ibn as-Salaah who is declared reliable by Ibn Hibbaan and al-Haakim, but is somewhat weak. Then the rest of its narrators are those of the Saheeh.” Ibn Yoonus said: “Weak and reprehensible things are reported from him (Rawh ibn as-Salaah).” Ad-Daaraqutnee said: “He (Rawh ibn as-Salaah) is daeef (weak) in hadeeth.” Ibn Maakoolaa said: “They declare him (Rawh ibn as-Salaah) weak.” Ibn ‘Adiyy said after quoting two of his hadeeth: “He reports many hadeeths and some of them are reprehensible.” So they agree upon his weakness, so his hadeeth is rejected (munkar) since he is alone in reporting it. Therefore this hadeeth can not be used to show that it is halaal to make tawassul through anyone as it is very weak.