﴿ فِىٓ أَدْنَى ٱلْأَرْضِ وَهُم مِّنۢ بَعْدِ غَلَبِهِمْ سَيَغْلِبُونَ ﴾

“in the lands close-by; yet it is they who, notwithstanding this their defeat, shall be victorious”

(In the nearer land) close to Persia and, as a consequence, the believers were aggrieved while the idolaters rejoiced, saying: " We shall defeat the believers just as the Persians defeated the Romans " , but then Allah proceeded to mention their victory (and they) i.e. the Romans, (after their defeat) at the hand of the Persians (will be victorious) over the Persians.