It is narrated from Sayyiduna Ubayy bin Ka'b (may Allah be pleased with him) that he asked: "O Messenger of Allah (peace and blessings be upon him), what is the reward of fever?" He (peace and blessings be upon him) said: "Good deeds keep flowing for the one with fever as long as his foot keeps stumbling (from weakness) or a vein keeps throbbing." Then he said: 'Allahumma inni as'aluka humma la tamna'uni khurujan fi sabilika wa la khurujan ila baytika wa la masjidi nabiyyika' (O Allah, I ask You for a fever that does not prevent me from going out in Your path, from going to Your House (the Ka'bah), or to the mosque of Your Prophet). So after that, whenever Sayyiduna Ubayy (may Allah be pleased with him) was touched, he had a fever.
No one except Muhammad bin Isa al-Tabba' (may Allah have mercy on him) narrated these two hadiths from Mu'adh bin Muhammad bin Ubayy (may Allah have mercy on him).
Hadith Referenceالمعجم الأوسط / باب الألف / 445
Hadith Gradingمحدثین:إسناده حسن
Hadith Takhrij«قال علي ابن المديني: إسناد مجهول «تعجيل المنفعة بزوائد رجال الأئمة الأربعة، ج 2، ص 209»» «قال ابن حجر: إسناده حسن «الإصابة في تمييز الصحابة، ج 1، ص 60»» «أخرجه الضياء المقدسي فى «الأحاديث المختارة» برقم: 1269، 1270، والطبراني فى «الكبير» برقم: 540»