It is narrated from Thabit bin Ubayd (may Allah have mercy on him) that he said: "I went to Sayyiduna Zayd bin Thabit (may Allah be pleased with him) to visit him while he was ill, and his two sons were with him. Meanwhile the iqamah for the prayer was called, so Sayyiduna Zayd (may Allah be pleased with him) said (instructing his sons): 'Both of you go to the prayer, for a man's prayer in congregation surpasses his prayer alone by twenty-five degrees.'"
Imam Musaddad recorded this athar (report) in his Musnad, and all its narrators are thiqat (trustworthy). This virtue of congregational prayer is also established by authentic marfu' hadith.
Hadith Referenceالمطالب العالية بزوائد المسانيد الثمانية / كتاب الصلاة / 401
Hadith Gradingمحدثین:إسناده صحيح
Hadith Takhrij«حکم الحدیث المطالب العالیہ محققاً تنسیق د. سعد بن ناصر بن عبد العزيز الشَّثري- مکتبہ شاملہ :إسناد صحيح » «أورده ابن حجر فى "المطالب العالية"، 336، 401، وأخرجه عبد الرزاق فى «مصنفه» برقم: 2025، وأخرجه ابن أبى شيبة فى «مصنفه» برقم: 4054، 4055، 8483، 8487، وأخرجه الطبراني فى«الكبير» برقم: 4936»