Tahdhib ut-Tahdhib – Ibn Hajr Asqalani, Publish: al-Risalah, Beirut/Lebanon
Imam Ibn Hajr Asqalani proving Yahyah Bin Yahya research said this proves Imam Ibn Hajr and Imam Hakim (rah) Belief (aqida) that going to tombs of Awliyas and asking through their Intercession is allowed. Ibn Hajr (rah) Writes: Imam Hakim (rah) said that he heard Abu Ali Nishapori that he said that I was in extreme depression that I saw Prophet (Peace Be Upon Him) in my dream he said that go to grave of Yahya bin Yahya (rah) and do Istaghfar and ask for help through his Intercession your problem will be solved. Abu Ali Nishapori said I did like that and my problem was solved in the morning. [Ibn Hajr, Tahdhib ut-Tahdhib Volume 004, Page 398]