In one narration the wording is: No one will enter Hell until he has seen his place in Paradise, had he done good (he would have got that place in Paradise); this will be so that it becomes a regret for him. And no one will enter Paradise until he has seen his place in Hell, had he done evil (he would have been given that place); this will be so that he becomes more grateful. Ahmad recorded all these narrations, and the narrators of the first narration are the narrators of the Sahih.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب أهل الجنة / 18661