A man came to the Prophet ﷺ and said to him, "My sister vowed to perform the Hajj, but she died (before fulfilling it)." The Prophet ﷺ said, "Would you not have paid her debts if she had any?" The man said, "Yes." The Prophet ﷺ said, "So pay Allah's Rights, as He is more entitled to receive His rights." (Using translation from Bukhārī 6699)   

أَنَّ رَجُلًا أَتَى رَسُولَ اللهِ ﷺ فَقَالَ إِنَّ أُخْتِي نَذَرَتْ أَنْ تَحُجَّ وَإِنَّهَا مَاتَتْ قَالَ لَوْ كَانَ عَلَيْهَا دَيْنٌ أَكُنْتَ قَاضِيَهُ؟ قَالَ نَعَمْ قَالَ فَقَالَ فَاقْضُوا اللهَ؛ فَهُوَ أَحَقُّ بِالْوَفَاءِ  

[Machine] I asked, "O Messenger of Allah, if my father is obligated to perform Hajj but he is an elderly man who cannot ride a camel, what should he do about performing Hajj?" He replied, "Yes, he can appoint someone to perform Hajj on his behalf." I asked, "O Messenger of Allah, what about the one among our people who dies without having made a will for Hajj? Can someone perform Hajj on their behalf?" He replied, "Yes, and you will be rewarded for it." I asked, "And can charity be given on their behalf and fasting be observed on their behalf?" He replied, "Yes, and charity is even better. Likewise, vows and walking to the mosques. This hadith is transmitted between the narrations of Ata' al-Khurasani and those above him, and it is also found in the established hadith before it."  

قُلْتُ يَا رَسُولَ اللهِ إِنَّ أَبِي أَدْرَكَتْهُ فَرِيضَةُ اللهِ فِي الْحَجِّ وَهُوَ شَيْخٌ كَبِيرٌ لَا يَتَمَالَكُ عَلَى الرَّاحِلَةِ فَمَا تَرَى الْحَجَّ عَنْهُ؟ قَالَ نَعَمْ فَحُجَّ عَنْهُ قَالَ يَا رَسُولَ اللهِ وَكَذَلِكَ مَنْ مَاتَ مِنْ أَهْلِينَا وَلَمْ يُوصِ بِالْحَجِّ فَيُحَجُّ عَنْهُ؟ قَالَ نَعَمْ وَتُؤْجَرُونَ قَالَ وَيُتَصَدَّقُ عَنْهُ وَيُصَامُ عَنْهُ؟ قَالَ نَعَمْ وَالصَّدَقَةُ أَفْضَلُ وَكَذَلِكَ فِي النَّذْرِ وَالْمَشْيِ إِلَى الْمَسَاجِدِ هَذَا مُرْسَلٌ بَيْنَ عَطَاءٍ الْخُرَاسَانِيِّ وَمَنْ فَوْقَهُ وَمَعْنَاهُ مَوْجُودٌ فِي الْحَدِيثِ الثَّابِتِ قَبْلَهُ