Hadith: My sister vowed to walk to the Sacred Mosque barefoot. Then, she asked me to ask the Messenger of Allah (may Allah's peace and blessings be upon him) about it. I asked him, and he replied: "Let her walk and ride."

عن عُقْبَة بْن عَامِرٍ رضي الله عنه قال: «نَذَرَتْ أُخْتِي أَنْ تَمْشِيَ إلَى بَيْتِ الله الْحَرَامِ حَافِيَةً، فَأَمَرَتْنِي أَنْ أَسْتَفْتِيَ لَهَا رَسُولَ الله صلى الله عليه وسلم فَاسْتَفْتَيْتُهُ، فَقَالَ: لِتَمْشِ وَلْتَرْكَبْ».
[صحيح] - [متفق عليه]

My sister took a vow to walk to the Sacred Mosque barefoot. Then, she asked me to ask the Messenger of Allah (may Allah's peace and blessings be upon him) about it. I asked him, and he replied: "Let her walk and ride."
[Authentic hadith] - [Narrated by Bukhari & Muslim]

Explanation

It is human nature to hasten sometimes and oblige oneself to do what is difficult. Islam has come with moderation and facilitation in the acts of worship so that one can continue performing them. In this Hadīth, ‘Uqbah ibn ‘Āmir's sister asked him to ask the Messenger of Allah (may Allah's peace and blessings be upon him) about her vow to walk to the Sacred Mosque barefoot. The Prophet (may Allah's peace and blessings be upon him) knew that she had the ability to walk some of the way. So, he ordered her to walk as long as she could and to ride when she could not.