Abu Sufyan narrates from his teachers that Sayyiduna Sa'd bin Abi Waqqas (may Allah be pleased with him) came to Sayyiduna Salman al-Farisi (may Allah be pleased with him) to visit him in his illness, and Sayyiduna Salman (may Allah be pleased with him) wept (from intense emotion). Sayyiduna Sa'd (may Allah be pleased with him) asked him: "O servant of Allah, what makes you weep? The Messenger of Allah (peace and blessings be upon him) departed from this world while he was fully pleased with you, and you will come to him (peace and blessings be upon him) at the Pond (al-Kawthar) and join your companions (who passed away before you)."
Imam Ahmad bin Mani' transmitted this narration; its narrators are thiqat (trustworthy), but there is a break in the chain because Abu Sufyan's teachers are unnamed. However, supporting reports for this incident exist in Sunan Ibn Majah and elsewhere.
Hadith Referenceالمطالب العالية بزوائد المسانيد الثمانية / كتاب المناقب / 4014
Hadith Takhrij«حکم الحدیث المطالب العالیہ محققاً تنسیق د. سعد بن ناصر بن عبد العزيز الشَّثري- مکتبہ شاملہ :—. » «أخرجه المستدرك للحاكم برقم: 7986، وأخرجه مصنف ابن أبي شيبة برقم: 35453، وأخرجه المعجم الكبير للطبراني برقم: 6160»