I heard Abu Qasim ﷺ say, "Some men will leave Madinah out of dislike for it, but Madinah is better for them, if only they knew."
حدثنا عبد الرحمن حدثنا حماد عن محمد قال سمعت
ل سمعت أبا القاسم ﷺ يقول يخرج من المدينة رجال رغبة عنها والمدينة خير لهم لو كانوا يعلمون
Its isnad is sahih. It appears in Jami al-Masanid 7:338, from this same place. It will also come again at 9226, 9994, 9995. I have not found it in this exact wording except in the Musnad, but its meaning is established within a longer hadith, narrated by Muslim 1:389 through Ala, from his father, from Abu Hurairah. See also 7852, 7853. Its meaning is also to be found within a hadith of Sufyan bin Abu Zuhayr, narrated as a marfu report, related by Malik in Muwatta p. 887–888, and transmitted by the two Shaykhs.