Why does the pilgrim who hastens depart on the twelfth day of Hajj, and the one who delays on the thirteenth, even though Allah says: "But whoever hastens off in two days..."?

The meaning of the verse: "But whoever hastens [his departure] in two days" is that the one who hastens leaves on the twelfth day of the Days of Tashreeq, which are the eleventh, twelfth, and thirteenth. The common misunderstanding is to consider the Day of Eid as the first of the two mentioned days, but the correct understanding is that the two days are from the Days of Tashreeq (the eleventh and twelfth), as Sheikh Ibn Uthaymeen mentioned, because the "numbered days" mentioned in the verse are the Days of Tashreeq.