This excerpt is taken from the book by Sheikh Abi Abdul Saboor Abdul Ghafoor Damni Fazail al-Jihad.
حدثنا شعبة قال سمعت قتادة قال سمعت أنس بن مالك رضى الله عنه عن النبى صلى الله عليه وسلم قال ما أحد يدخل الجنة يحب أن يرجع إلى الدنيا وله ما على الأرض من شيء إلا الشهيد يتمنى أن يرجع إلى الدنيا فيقتل عشر مرات لما يرى من الكرامة.
"Sha'bah narrated to us, he said: I heard Qatadah say, he said: I heard Anas bin Malik (may Allah be pleased with him) say that the Prophet Muhammad (peace be upon him) said: 'There will be no person who, after entering Paradise, would wish to return to the world even if he were given the whole world, except a martyr who would wish to return to the world and be killed ten times over, because he sees the honor of martyrdom in Paradise.'"
Reference: (Sahih Bukhari and Muslim) (Narrated by Bukhari, Book of Jihad and Expedition, Chapter: The desire of the Mujahid to return to the world, wording as it is, Number: 2817 / Muslim, Book of Leadership, Chapter: The virtue of martyrdom in the way of Allah, Number: 1877)
Explanation
A person who is martyred in jihad is immediately admitted to Paradise. The life of a martyr has no connection with the life of this world.
Imam Ibn Battal, may Allah have mercy on him, states that only jihad is the righteous deed in which the struggler risks his life; therefore, Allah Almighty has also assigned a great reward for it.