In a dream they are the attainment of what one desires. Seeing them may signify both victory and defeat. God the Exalted said:
الٓمٓ غُلِبَتِ ٱلرُّومُ فِىٓ أَدْنَى ٱلْأَرْضِ وَهُم مِّنۢ بَعْدِ غَلَبِهِمْ سَيَغْلِبُونَ فِى بِضْعِ سِنِينَ ۗ لِلَّهِ ٱلْأَمْرُ مِن قَبْلُ وَمِنۢ بَعْدُ ۚ وَيَوْمَئِذٍ يَفْرَحُ ٱلْمُؤْمِنُونَ
“Alif, Lām, Meem. The Byzantines have been defeated In the nearest land. But they, after their defeat, will overcome Within three to nine years. To Allāh belongs the command [i.e., decree] before and after. And that day the believers will rejoice”
Quran 30:1–4 · Saheeh International
— to the end of the verse.