Shu'ayb bin Dinar (may Allah have mercy on him) says: I heard 'Abdulwahhab bin Bakht al-Makki (may Allah have mercy on him) say: When the battle is intense, if possible, perform the prayer standing; otherwise, while riding; and if that is not possible, then say the takbir; and if even that is not possible, then at the very least, keep mentioning the prayer in your heart.
Hadith Referenceسنن سعید بن منصور / كتاب التفسير / 413
Hadith Gradingمحدثین:سنده ضعيف؛ إسماعيل بن عياش تقدم في الحديث [٩]
Hadith Takhrij«أخرجه سعيد بن منصور فى (سننه) برقم: 413، 2516»