Mishkat al-Masabih 3834
Al-Miqdam b. Ma'dikarib reported God’s Messenger as saying, “The martyr receives six1 good things from God:
he is forgiven at the first shedding of his blood, he is shown his abode in paradise, he is preserved from the punishment in the grave, he is kept safe from the greatest terror2, he has placed on his head the crown of honour a ruby of which is better than the world and what it contains, he is married to seventy-two wives of the maidens with large dark eyes,3 and is made intercessor for seventy of his relatives.” 

1. There seem to be seven things mentioned in this tradition.
2. Cf. Al-Qur'an; 21:103.
3. Cf. Al-Qur’an, 56:22.

Tirmidhi and Ibn Majah transmitted it.
وَعَنِ الْمِقْدَامِ بْنِ مَعْدِي كَرِبَ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: 
" لِلشَّهِيدِ عِنْدَ اللَّهِ سِتُّ خِصَالٍ: يُغْفَرُ لَهُ فِي أوَّلِ دفعةٍ وَيَرَى مَقْعَدَهُ مِنَ الْجَنَّةِ وَيُجَارُ مِنْ عَذَابِ الْقَبْرِ وَيَأْمَنُ مِنَ الْفَزَعِ الْأَكْبَرِ وَيُوضَعُ عَلَى رَأْسِهِ تَاجُ الْوَقَارِ الْيَاقُوتَةُ مِنْهَا خَيْرٌ مِنَ الدُّنْيَا وَمَا فِيهَا ويزوَّجُ ثنتينِ وَسَبْعِينَ زَوْجَةً مِنَ الْحُورِ الْعِينِ وَيُشَفَّعُ فِي سَبْعِينَ مِنْ أَقْرِبَائِهِ ". رَوَاهُ التِّرْمِذِيُّ وَابْنُ مَاجَهْ