How authentic is the saying, "Between us and them are the funerals"?

The saying of Imam Ahmad, "Tell the people of innovation: 'Between us and you is the Day of Funerals'," is authentically attributed to him, and his foresight proved true. An immense number of people attended his funeral, while in his era, people shunned the funerals of the people of innovation. Imam Ahmad did not intend this to apply to all funerals in general, but rather to specific situations where the extent of people's attendance at funerals is determined by the deceased's level of knowledge and religiosity, or when the Ahl al-Sunnah (definition) (People of the Sunnah) are afflicted and people turn away from them during their lives, but then, upon their death, people desire to attend their funerals. This saying applies to the era of Imam Ahmad, when the righteousness of people and their love for religion and scholars prevailed. It does not apply to all times and circumstances, and it is not a general religious text.