5 Or 50 Salat And Bani Israel
As I see it, Ghamidi sb. didnt base his opinion on any riwayat. His argument (Rooya) comes from Quran. To those (the other group) who like to believe it was a physical journey (and they source it from Rivayaats), Ghamidi sb. pointed out that narration ends by suggestion it was Rooya. I hope that helps. Re. 50 vs. 5. We know it has always been 5 (details in link posted above). What might be the reason for 50 prayers negotiated down to 5 as explained in Riwayat? If Riwayat is correct in all details (we will never know) then it could highlight importance of Namaz in Islam for a believer (my two cents).
Completely agreed with the reasoning of Rooya; that’s completely understandable and no question about that. In my understanding (and as you implied), Ghamidi shb uses riwaayats only as a secondary support (and not to base his arguments) but even in the secondary support, he takes the ones in which he has satisfaction in chain and in content. That’s why I was a bit puzzled about the 50 number when it was coming from him. Your take regarding signifying the importance of salah is somewhat acceptable but, with due apologies, I wouldn’t find it convincingly enough since (according to hadeeth) Allah said, “ I have written 50 salahs in Loh-e-Mahfooz”. This goes a bit beyond than just signifying the importance and more of a decision.