It is narrated from Sayyiduna Salman al-Farisi (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "The first of you to reach me at the Pond of Kawthar will be the one who was the first of you to accept Islam, and he is Ali bin Abi Talib (may Allah be pleased with him)."
Imam al-Harith recorded this narration in his Musnad; however, in its chain there is a narrator named Yahya bin Hashim al-Ghassani, who according to the imams of hadith is severely discredited, a liar and a forger (one who fabricates hadith); therefore this narration is at the level of mawdu' (fabricated).
Hadith Referenceالمطالب العالية بزوائد المسانيد الثمانية / كتاب المناقب / 3925
Hadith Gradingمحدثین:إسناده موضوع
Hadith Takhrij«حکم الحدیث المطالب العالیہ محققاً تنسیق د. سعد بن ناصر بن عبد العزيز الشَّثري- مکتبہ شاملہ :إسناده موضوع » «أخرجه المستدرك للحاكم برقم: 4687، وأخرجه المعجم الكبير للطبراني برقم: 6174»