It is narrated from Sayyiduna Jabir (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said regarding Sayyiduna Sa’d: "He was a righteous man, at whose death even the Throne of Allah shook, and all the gates of the heavens were opened for him. At first, he was subjected to hardship, but then Allah granted him ease."
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 14505
Hadith Gradingحکم دارالسلام:صحيح لغيره، وهذا إسناد فيه انقطاع، فإن معاذ بن رفاعة لم يسمعه من جابر، وانظر: 14873 و 14153