الآية رقم (21) - يَا قَوْمِ ادْخُلُوا الأَرْضَ المُقَدَّسَةَ الَّتِي كَتَبَ اللّهُ لَكُمْ وَلاَ تَرْتَدُّوا عَلَى أَدْبَارِكُمْ فَتَنقَلِبُوا خَاسِرِينَ

(21) - (O my people, enter the Holy Land which Allah has assigned to you and do not turn back [from fighting in Allah 's cause] and [thus] become losers.)

(… الَّتِي كَتَبَ اللَّهُ لَكُمْ …) (…which Allah has assigned to you ): That is, it is obligatory for you to enter this Holy Land. Here the promise to enter is legislative and not a definite fact. And we can clarify the legislative will by Allah’s saying:

 }وَمَن دَخَلَهُ كَانَ آمِنً{

(And whoever enters it shall be safe.) (Ali-Imran: 97)

This is legislative, for many incidents occur inside the Haram, such as cases of theft, and what is meant here: You must secure those who enter the Haram.

(  وَلَا تَرْتَدُّوا عَلَىٰ أَدْبَارِكُمْ فَتَنقَلِبُوا خَاسِرِينَ … ) (and do not turn back [from fighting in Allah ‘s cause] and [thus] become losers ): Had it been a certain fact, they would not have turned back because nothing can act against Allah’s will.