2. Go ye then for four months backwards and forwards (as ye will) throughout the land but know ye that ye cannot frustrate Allah (by your falsehood) but that Allah will cover with shame those who reject him.

Notes (Tafseer)

1247. Four Months: Some Commentators understand by this the four forbidden months in which warfare by ancient Arabian custom was unlawful, viz., Rajab, Zul-qa'dah, Zul-hijjah, and Muharram: See ii. 194 n. But it is better to take the signification of the four months immediately following the Declaration. Assuming that the Sura was promulgated early in Shawwal (see Introduction), the four months would be Shawwal, Zul-qa'dah, Zul-hijjah, and Muharram, of which the last three would also be the customary Prohibited Months.