Secondly, Jannah is one of the many rewards.
i did not say that calling it jannatu'l baqiy is a sin or something like that - just letting you know that in my meagre knowledge, and the little what i have read, ulama have mentioned baqiy as only that. i checked a number of books - histories of madinah, sirah books, manasik - and invariably, they refer to the place as baqiy or baqiy al-gharqad. i checked persian/urdu books and manuals like
jazb al-qulub of shah abdu'l Haq and
bahar e shariat /
anwar al-bisharah and mawlana naqi ali khan's
jawahiru'l bayan fi asrari'l arkan. please correct me if i have missed it, but i didn't see jannat and only baqiy or ahl e baqiy here.
the closest to 'jannat' is a comment we find in
wafa'a of samhudi [d.911] that the enclave where mothers of believers are buried was called: 'rawDah ummuhat al-mu'minin' and close to it is the 'rawDah aqeel'. he quotes ibn jubayr mentioning in his travelogue as:
"the rawDah of aqeel, and the rawDah of mother's of believers..
...and facing it a short patch of verdant land (rawDah) in which three children of the Prophet sallAllahu alayhi wa sallam rest. and behind it is the rawDah of `abbas ibn `abd al-muTTalib.."
rawDah being a lawn, or meadow, or a small garden can then be stretched to a jannah.
Allah ta'ala knows best.
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[see wafa'a al-wafa'a of samhudi, 3/101, dar kotob ilmiyah ed.2006. wafa'a is perhaps the most comprehensive history of madinah; and certainly it is an authoritative reference.]