Answer
(Fatwa: 638/638/M=1433)
There is no opinion favouring 38 or 40 miles. Regarding the journey distance, there are four opinions in Shami etc: 63, miles, 54 miles, 48 miles, and 45 miles. The majority of the Fiqh scholars preferred 48 miles which at present is 77.25 kilometres. Hence if someone makes intention to set out on a journey of 77.25 km or more from his native place, then qasr is wajib on him.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband