It is narrated from Qays bin Abi Hazim (may Allah have mercy on him) that he said: "I saw Sayyiduna Abu Bakr al-Siddiq (may Allah be pleased with him); he was a lean, slender-bodied man with little flesh on his body, and he was a man of a very white (fair) complexion."
Imam Ahmad bin Mani' narrated it in his Musnad, and all the narrators of its chain are thiqat (trustworthy) and reliable.
Hadith Referenceالمطالب العالية بزوائد المسانيد الثمانية / كتاب المناقب / 3868
Hadith Gradingمحدثین:إسناده صحيح
Hadith Takhrij«حکم الحدیث المطالب العالیہ محققاً تنسیق د. سعد بن ناصر بن عبد العزيز الشَّثري- مکتبہ شاملہ :إسناده صحيح » «أخرجه المعجم الكبير للطبراني برقم: 25»