Musnad Ahmad 340
It was narrated from Ibn Seereen, who heard it from Abul-`Ajifa` who said:
I heard `Umar say: Do not make women`s dowries too expensive, for if it were a sign of honour in this world or a sign of piety in the Hereafter, the most likely of you to do it would have been the Prophet (ﷺ). But he did not give any of his daughters in marriage or marry any of his wives for more than twelve Ooqiyyah, Furthermore, you say during your campaigns. So and so was killed as a martyr, So and so died as a martyr, but perhaps he loaded his mount`s back with gold and silver, hoping to do trade. So do not say that; rather say as Muhammad  said: “Whoever died for the sake of Allah is in Paradise.”
حَدَّثَنَا سُفْيَانُ، عَنْ أَيُّوبَ، عَنِ ابْنِ سِيرِينَ، سَمِعَهُ مِنْ أَبِي الْعَجْفَاءِ، سَمِعْتُ عُمَرَ، رَضِيَ اللَّهُ عَنْهُ يَقُولُ لَا تُغْلُوا صُدُقَ النِّسَاءِ فَإِنَّهَا لَوْ كَانَتْ مَكْرُمَةً فِي الدُّنْيَا أَوْ تَقْوَى فِي الْآخِرَةِ لَكَانَ أَوْلَاكُمْ بِهَا النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ مَا أَنْكَحَ شَيْئًا مِنْ بَنَاتِهِ وَلَا نِسَائِهِ فَوْقَ اثْنَتَيْ عَشْرَةَ وُقِيَّةً وَأُخْرَى تَقُولُونَهَا فِي مَغَازِيكُمْ قُتِلَ فُلَانٌ شَهِيدًا مَاتَ فُلَانٌ شَهِيدًا وَلَعَلَّهُ أَنْ يَكُونَ قَدْ أَوْقَرَ عَجُزَ دَابَّتِهِ أَوْ دَفَّ رَاحِلَتِهِ ذَهَبًا وَفِضَّةً يَبْتَغِي التِّجَارَةَ فَلَا تَقُولُوا ذَاكُمْ وَلَكِنْ قُولُوا كَمَا قَالَ مُحَمَّدٌ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ مَنْ قُتِلَ فِي سَبِيلِ اللَّهِ فَهُوَ فِي الْجَنَّةِ‏.‏